FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: 440sixpack on December 15, 2018, 07:26:41 PM
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In the process of getting my 428 back together. it came with a perfectly tuned Edelbrock that runs great but I run a Holley on everything.
I have a brand new 770 Truck Avenger I got somewhere. would this be too much for a street 428 with 10-1 compression , a mild roller cam and pretty much stock otherwise. this is in a '76 high boy with a 4spd. I think I'd be better off with a 650 but if this would work I have it.
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The 770 is not too big. I don't know what makes it a "truck" carb though?
Just for comparison, I ran my 68 F250 Highboy with a stock S intake, which is very similar to yours, and it did a great job. My engine would have been similar to yours also, except it was a 390. Mild solid cam that resembled the Ford 390 "GT" cam, headers, C4 heads...and a 750 VS Holley. That carb/intake duo worked perfectly for that combo, idled great, had tons of low end grunt and pulled really nice to about 5000 rpms, where the cam started to give out. A better intake might make a little more power, but I doubt you'd feel it, and it also might kill a bit of the lower end. My truck got used, hard, for almost 25 years, so I was ok with the minor trade-off. I think you'll be pleasantly pleased with your combo, provided it's tuned right.
Edit to add that, personally, I think the 650 would kill more power than anything but the factory log exhaust. A 428 is a fairly good sized engine; bigger than a 650 can feed.
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The Truck Avenger carb has some strange futures in them you have to take care of, better have Drew to advise you on that part, the 770cfm is not a trouble.
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The Truck avenger series has a stupid vent tube in the air horn for extreme off road angles or something. just something to make Bubba feel like he has a special carb I guess.
As far as the rest goes it looks pretty much like a run of the mill street avenger. but maybe I need to check it out.
Holley calls for a 570 to a 650 in there carb selector, but they always lean to the small side it seems.
Do you think I should break in the rings with the Edelbrock and then switch it afterwards ? I don't know how the jetting will be so it might be a bit rich.
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Carb calculators always seem to be on the conservative side compared to what actually works best, or what an engine can use.
It's always best to do a break-in with a known good carb. The last thing you want is a lean or rich condition during that crucial stage. It would even be wise to do some initial driving with the known good carb, then switch it out after everything gets broken in.
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A 750 vacuum secondary is my go to carb on anything but the mildest truck FEs. 360s and real mild 390s can be happy with a 600, but your build should be happy with a 750-770
FWIW, my temporary truck motor, tight quench std bore 390 4V, mild Crane hyd flat tappet, Streetmaster, and headers runs perfect with a 750, so it's certainly not too much carb for a 428 with more cam and likely more compression. In fact, it runs so nice I am questioning why I am building the EFI 461 for it right now :)
The 770 is not too big. I don't know what makes it a "truck" carb though?
Just for comparison, I ran my 68 F250 Highboy with a stock S intake, which is very similar to yours, and it did a great job. My engine would have been similar to yours also, except it was a 390. Mild solid cam that resembled the Ford 390 "GT" cam, headers, C4 heads...and a 750 VS Holley. That carb/intake duo worked perfectly for that combo, idled great, had tons of low end grunt and pulled really nice to about 5000 rpms, where the cam started to give out. A better intake might make a little more power, but I doubt you'd feel it, and it also might kill a bit of the lower end. My truck got used, hard, for almost 25 years, so I was ok with the minor trade-off. I think you'll be pleasantly pleased with your combo, provided it's tuned right.
Edit to add that, personally, I think the 650 would kill more power than anything but the factory log exhaust. A 428 is a fairly good sized engine; bigger than a 650 can feed.
Doug, they certainly can run well with the S intake, and I would never say an uintake is required, but I can tell you, when mine worked for a living I went from an S to a 428 PI and it was night and day with no other changes. Same carb, same distributor, just an on the truck intake change. The truck at the time was a 390 + .030 low compression with the 204/214 cheapo cam sold through NAPA, bone stock D2TE-AA heads, 600 1850 with a set of headers.
I've told the second half of the story before, but about a year later was when the Performer 390 came out, I swapped the PI because the exhaust crossover rotted out and the Performer was such a turd on the whole curve, I fixed the PI intake and swapped it right back.
This was a long bed 4x4 NP435 4 speed at the time, with 3.70 gears and 36 inch rubber, plowed snow, pulled anything I needed back to the shop and it really gained everywhere and no loss whatsoever. I certainly think the S and T code intake have their place, but IMHO a mild 390 out breathes them pretty quick
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Since my name was brought up......
Truck avengers are weird.
If I had one carb to pick, it would be this:
(https://farm5.staticflickr.com/4806/31023400667_cf483593d3_c.jpg) (https://flic.kr/p/Pgr3bp)IMG_1132 (https://flic.kr/p/Pgr3bp) by Drew Pojedinec (https://www.flickr.com/photos/154777202@N07/), on Flickr
(https://farm5.staticflickr.com/4839/46295709352_02aa35f62a_c.jpg) (https://flic.kr/p/2dwZBto)IMG_1137 (https://flic.kr/p/2dwZBto) by Drew Pojedinec (https://www.flickr.com/photos/154777202@N07/), on Flickr
These EH 780's work well on 390's, 428's, heck most everything to be honest.
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Anything in particular on a truck avenger to be aware of ?
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Since my name was brought up......
Truck avengers are weird.
If I had one carb to pick, it would be this:
(https://farm5.staticflickr.com/4806/31023400667_cf483593d3_c.jpg) (https://flic.kr/p/Pgr3bp)IMG_1132 (https://flic.kr/p/Pgr3bp) by Drew Pojedinec (https://www.flickr.com/photos/154777202@N07/), on Flickr
(https://farm5.staticflickr.com/4839/46295709352_02aa35f62a_c.jpg) (https://flic.kr/p/2dwZBto)IMG_1137 (https://flic.kr/p/2dwZBto) by Drew Pojedinec (https://www.flickr.com/photos/154777202@N07/), on Flickr
These EH 780's work well on 390's, 428's, heck most everything to be honest.
The downleg Holley 780 3310-1 is the overall best musclecar carb ever, in my opinion. Factory installed on 302's, 396's, and 454's. Works well on 14 second cars, and all the way to 9 second cars. Amazing carb.
paulie
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Anything in particular on a truck avenger to be aware of ?
Well..... they were built for one reason. Offroading and the truck being at weird angles.
So yeah, it's cool for rock climbing. I don't do any of that, so the carb is kinda just "meh" in daily driver status.
I know, I know, I'm a carb guy, but I think if I was doing serious rock climbing I'd be using fuel injection.
I'd have to look at my notes, but the emulsion is drastically different, and if I recall the two that came in, both where fighting lean spike issues.
Try it out, you've already got it....
The downleg Holley 780 3310-1 is the overall best musclecar carb ever, in my opinion. Factory installed on 302's, 396's, and 454's. Works well on 14 second cars, and all the way to 9 second cars. Amazing carb.
paulie
There are a handful of others that work really really well all around, but the 3310EH and -1 are so common, it's hard for me not to use them as a go-to carb when someone asks for a mild performance suggestion.
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I'll give it a try but if it doesn't run great I'll ditch it.
I know there are a million variables but don't you think 74 main jets on a mild built 428 at 3000 foot elevation might be a little rich? they say that's what they come with so I was thinking more like a 68 the 670 comes with to start with.
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I know there are a million variables but don't you think 74 main jets on a mild built 428 at 3000 foot elevation might be a little rich? they say that's what they come with so I was thinking more like a 68 the 670 comes with to start with.
Jetting isn't like an on/off switch.... jetting isn't engine specific. Jetting is venturi and throttle plate specific with a dash of signal thrown in the mix.
For example, If I put a 600cfm carb on a 445 stroker, my main jet would be 66-67, really not gonna be a ton more or less. If I had to go over 68 I'd start looking to see what is out of whack.
Now, toss on a 750 carb and all of a sudden I'm running 72-74 jets.
Toss on a 780 downleg carb like I pictured above and we are running 68 jets... why less? air bleed differences, booster differences, PVCR's that are massive, plus from the factory that early 3310 had a 10.5 power valve, so you can cruise lean and clean, push the throttle a little the the power valves starts to pull open.
Same reason I can run 1, 750 carbs on a 445ci engine and run 72 jets. Add two carbs? Probably gonna run 70 or 72 jets again :P Each restriction is being pulled on half as hard. Knock out those downlegs and install Annular boosters and all of a sudden 72 jet is stupid rich and you are jetting down to 66 just to get in the neighborhood
blah blah blah, just bolt on the truck avenger and see what happens. (be better still to go test it on a known good engine)
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Makes sense.
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The downleg Holley 780 3310-1 is the overall best musclecar carb ever, in my opinion. Factory installed on 302's, 396's, and 454's. Works well on 14 second cars, and all the way to 9 second cars. Amazing carb.
paulie
There are a handful of others that work really really well all around, but the 3310EH and -1 are so common, it's hard for me not to use them as a go-to carb when someone asks for a mild performance suggestion.
Are there any significant differences between an EH 3310 and a 3310-1?
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EH has a different secondary metering block, and a .002 larger IAB. It also has Chevy specific throttle shaft and the driver side has 1/4'' NPT threaded into the main body for some accessory that the -1 does not have.
Otherwise they function pretty much the same. I bring them both up so if someone is looking for one at a swap meet, they would know that they are both desirable.
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EH has a different secondary metering block, and a .002 larger IAB. It also has Chevy specific throttle shaft and the driver side has 1/4'' NPT threaded into the main body for some accessory that the -1 does not have.
Otherwise they function pretty much the same. I bring them both up so if someone is looking for one at a swap meet, they would know that they are both desirable.
Thanks!
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You got some very good answers here, I have one way to simplify the jet discussion though (maybe too much even) but just the same....
Everyone understands that you need an "air / fuel mixture" it's a ratio of one to the other, goal is between about 12:1 - 14:1 depending on what the engine is doing.
So, if you increase the size of the carb in CFM (air flow) then you need increase the fuel too (jet size) So in very basic terms, although a jet for a 770 seems large compared to a 600 it has to be., the air is increased so the fuel needs to be
Now Drew is likely ready to jump at me because it isn't that simple, other sources that contribute to the jet size required are secondary sources of fuel (power valve channel restriction...another jet that feeds in at low vacuum), booster design, emulsion circuit design, air bleeds, etc, but overall, a bigger carb has to have more fuel from somewhere and usually, it's more main jet
An example, a garden variety 850 takes an 80/88 jet combo, with the secondaries not having a powervalve, so bigger carb, bigger jet, and then when you take away a power valve out back, even bigger jet. So you can see how much those other sources come into play.
Last thing, I do not expect you will love that Avenger series without work unless you get lucky. They can act goofy at times, although I haven't specifically used a TRUCK avenger. The Street Avenger series in general has used an odd emulsion circuit that delays the transition from idle to main fuel. Some combos (and some people) don't care, some have a slight hesitation or bucking when lightly accelerating. It's worth trying if you have the carb, especially if it's an engine with decent vacuum. Also, it's easily fixed by someone like Drew if it bothers you, but other than that, it's really just a decent carb with funny vents and I think a little more float control.
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Nah, I won't string you up, lol.....
Ross, the truck avenger, you'd love it. Has mini annular boosters in the primary with no HSAB. Typically they are fat at idle, stupid lean off idle, and really fat as the idle feed and boosters run together for about 1200rpms.
Have downlegs in the secondary but it doesn't matter, they'll never open anyway.
As far as fixing one, my advice has always been to just sell it on ebay and start with something that needs less work.
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Nah, I won't string you up, lol.....
Ross, the truck avenger, you'd love it. Has mini annular boosters in the primary with no HSAB. Typically they are fat at idle, stupid lean off idle, and really fat as the idle feed and boosters run together for about 1200rpms.
Have downlegs in the secondary but it doesn't matter, they'll never open anyway.
As far as fixing one, my advice has always been to just sell it on ebay and start with something that needs less work.
LOL definitely different than a Street Avenger, not that I like those that much either.
It's amazing what Holley does to "improve things"
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It's amazing what Holley does to "improve things"
LOL
Some of the newer stuff can be pretty good - but some of it is so wrong that it hurts.
Like an annular booster with no HSAB...who thought that was a good idea?
I really like those old 3310 780s and the CJ 735s.....still about the best OE calibrations for drivability and smooth street performance. They simply drive really well.
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Bored and want to do some reading Ross?
https://www.tapatalk.com/groups/racingfuelsystems/viewtopic.php?f=25&t=1683&p=16284&hilit=truck+avenger#p16284
I like the 735 CJ stuff as well, I didn't mention it as they are often expensive. I just scored 4 of them for cheap, hope to do them sometime in the next month or two.
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Wow thanks Drew. I wonder what they ever wanted to accomplish with that 670? Can't say I'd want to have to try to make one of those work
There has to be something acting like a HSAB in there, I just can't see the liquid fuel behaving nicely without something in a circuit. A kill bleed in the booster itself maybe?
Does the 770 have the same setup?
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I think the 770 has downleg secondaries.
The few that came in were a few years ago and I didn’t write down calibrations at that time.
The angle channel is high, so no kill bleed or siphon break needed.
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Wow thanks Drew. I wonder what they ever wanted to accomplish with that 670? Can't say I'd want to have to try to make one of those work
There has to be something acting like a HSAB in there, I just can't see the liquid fuel behaving nicely without something in a circuit. A kill bleed in the booster itself maybe?
Does the 770 have the same setup?
I have a 390cfm Holley R6390 from a 392cid International Harvester truck.
Same deal, PMAB=0 on the main body, all PMAB=0 on the block.
PIAB=.070", big, like this 670sa carb.
The R6390 runs really strong (on a little engine), it has won more GTECH shootouts on my 6cyl inline than any other carb.
So they must have done something right in there.
All 4 boosters are regular straight-leg, and the secondary bleeds all look pretty normal as do the jets.
Why go to this configuration of PMAB==0 everywhere? Strange!
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For what ever reason Holley made there choice to calibrate the truck avenger carbs that way those carbs don't function properly on a regular car 200 ore 500 Hp dosent matter. It will take a skillful person like Drew to rework it to function on a car ore even a truck what that matters.
Get another carb or rework it.
The idea with the Main Air Bleed is to lean out the fuel curve in the upper part of the curve because the signal to the booster increases whit air flow in a not linear path so the carb will turn overly rich otherwise.
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Okay, so everything I hear and read on the truck avenger is it's a POS.
The 3310 EH sounds like a good option, I see lots of them on ebay. but I don't want to buy a worn out junker with mismatched parts and cracked housings and try to fix it. so what would be a viable alternative in something new ? All I see are street avengers and double pumpers and I don't need that for a 4x4.
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I have little experience with new carbs, and can't advise there.
I have about a dozen EH or -1 3310's that I could restore. It'll cost roughly the same as a new Avenger, but it'll be blueprinted and I test run them. It'll look like the ones I posted above.
I didn't mean to participate in this thread and make it seem like a for sale dealio......
What you have:
-Edelbrock that runs great
-Truck avenger that hasn't been tested.
Given what you have on hand I'd either run the Edelbrock, or test out the truck avenger on a known good engine. I would be scared to test an unknown carb on a new engine.... just too many things to be watching for.
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I don't like to introduce too many variables at once because if something goes wrong it's really hard to figure out what exactly the problem is.
The Edelbrock, even if it's too small, would be my choice first. One less thing to worry about. Once everything is dialed in, then switch to something else so there is only one variable to deal with. Especially if you run that Avenger. I'm no carb expert, but I haven't had good luck with "newer" Holleys except for a few "race" carbs and even then some of those didn't work. I got an XP last year that had a bad mainbody out of the box.
Someone who is good at carbs can fix an avenger, but I haven't had one that every really worked right.
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I had a 870 street avenger it had a slight delay
untill i put on a fourhole spacer or adjusted the
floatlevel to high
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Drew, I'll give that new carb I have a try but if it gives any trouble at all you'll be hearing from me.
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Claimed NOS, posted for coloration reference. Could this finish really have stayed like this since new?
https://phoenix.craigslist.org/evl/pts/d/mesa-1966-chevelle-ss-396-nos-holley/6772601106.html
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Claimed NOS, posted for coloration reference. Could this finish really have stayed like this since new
Yes.
Even on nasty cores you can often see the original coating in places. Under the VS lid is typically a good place to look for it.
Tho typically they don’t look that great brand new
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Claimed NOS, posted for coloration reference. Could this finish really have stayed like this since new
Yes.
Even on nasty cores you can often see the original coating in places. Under the VS lid is typically a good place to look for it.
Tho typically they don’t look that great brand new
Is the Holley refinishing service able to do this? I wonder, considering the asking price, if this is indeed NOS. My old Holleys look like they were painted on the same assembly line as Patton tanks. Maybe all those heat cycles frig the plating.
The question another person and myself have discussed is, if an enthusiast is able to dead-replicate the random coloring for concourse use, how long is going to be before it it discolors again? Replating every few years would have to get tiresome.
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Ok, to answer your questions....
-Holleys refinishing service looks kinda meh in my opinion. Several months ago they outright stopped trying to do restorations.
-as far as longevity, the original chromate work didn’t need to be good. It was working with freshly poured castings. As such the skin on them was super clean and rich. To get older carbs back to that level of molecularly clean takes a ton of work. Simply put for some originals I don’t bother. For proper restorations you obviously go the distance. Still. If an impurity is below the surface and I have the skin looking right, over time it’ll oxidize and degrade in appearance. Ie a 55 year old casting has seen some stuff
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Oh, let me make sure you know this first.... the castings are NOT plated.
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Oh, let me make sure you know this first.... the castings are NOT plated.
What are they then?
Personally, I never really cared much for the original finish on Holleys. Aesthetically, they clash with virtually every component on every engine. I do have to address originality on the cars I have that demand that. Otherwise, I am fine with powder coating some color that looks better to me. Black with silver or gold hardware looks good, I think.
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Chromates are conversion coatings.
Holleys are made of Zamac3 zinc alloy.
That is where the color comes from. There is no need to plate the main body or bowls etc.
This is why it’s so hard to do this restoration deal. It isn’t like I’m painting the parts, it’s like using ospho on steal to get it to turn the right shade of black
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Chromates are conversion coatings.
Holleys are made of Zamac3 zinc alloy.
That is where the color comes from. There is no need to plate the main body or bowls etc.
This is why it’s so hard to do this restoration deal. It isn’t like I’m painting the parts, it’s like using ospho on steal to get it to turn the right shade of black
What do you think of this video? https://www.youtube.com/watch?v=Nmn94B5UUuU
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I think it’s a video of a fella plating castings and sticking his ungloved hand into hexavalent chromium.
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Freezing the video at 22:05 or thereabouts and comparing that carb to the NOS piece on Craigslist, I see a pretty decent match. The "rainbow" is apparent on both. So, semantics aside, why wouldn't I want to follow the vid sequence if I were trying my best to achieve an OEM appearance? Who is going to walk up to a car with this carb and tell the owner it doesn't look right? Trying all angles here. Not going into biz like you, but I do have a bunch of Holleys sitting here that I'm going to have to dial in with a plan at some time. I promise to wear gloves.
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Video is a video. Seeing it in real life it’s different.
Do whatcha want. Just be real careful, that chloride solution will be intensely corrosive to internal passages. So remove emulsion tubes and clean the wells after plating.
Also pin gauge and blueprint the carb as plating can change hole sizes.
If the castings aren’t perfectly clean you can contaminate you chloride bath. Water wash super well as the chloride solution will spoil your chromates.
As far as what to do with your Holleys, I’d suggest selling them as cores to someone who will properly preserve them. Spending thousands of dollars, practicing on hundreds to get decent results, taking roughly 10-14 hours a carb assuming you did a decent job leaves little profit compared to just selling the cores.
I will mention that of all the restorers I know, I know of zero Holley restoration folks that plate castings.
Good luck
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As far as what to do with your Holleys, I’d suggest selling them as cores to someone who will properly preserve them. Spending thousands of dollars, practicing on hundreds to get decent results, taking roughly 10-14 hours a carb assuming you did a decent job leaves little profit compared to just selling the cores.
Um, selling off the original carbs that belong to the legions of complete QRSMN etc cars I have doesn't make too much sense, does it? Profit, again, is for rebuilders, and does not enter the equation here. Complete muscle cars with correct parts is the game.
Buyer: Gorgeous R-code XR7 you have. Gee, what carb you got on there?
FElony: It's an Endurashine Edelbrock. It's shiny!!
Buyer: Where's the original?
FElony I sold it cheap as a core because Drew said I couldn't make a profit on it.
Buyer I'll give you $5000 less than your bottom dollar, since this carb is incorrect.
FElony Well, OK. :'(
I will mention that of all the restorers I know, I know of zero Holley restoration folks that plate castings.
Good luck
Well then, what's the secret? You can PM me. I won't tell. ;)
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You said you had a bunch of carbs, not a bunch of cars, so don’t act like that. Cheapest/best thing for you to do? Get someone to restore a carb before you sell each car. I can give you suggestions on who to call for restoration work.
Or do it yourself.
There is no secret, buy the supplies, spend 16 hours a day practicing for a year or so to where you get decent, and get her done. Don’t practice on those originals as you will most likely destroy several while figuring it all out. You have your you tube videos.
Good luck.
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OK, thanks for your help.
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I think it’s a video of a fella plating castings and sticking his ungloved hand into hexavalent chromium.
I am not particularly fond of home/hand plating or dichromating.
It tends to be hard on friends.
I actively caution those I know that do it.
An unusually high percentage of good folks I knew from Holley left this earth early from cancers that should not have been that common in guys that age.
Impossible to draw a scientific conclusion other than the fact that they all were actively involved in small batch hand plating on custom and/or prototype parts, and I cannot call any of them on the phone....
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I am not particularly fond of home/hand plating or dichromating.
It tends to be hard on friends.
I actively caution those I know that do it.
Rightfully so..... This is made worse by small time "hobbiest" places selling chemicals without tech sheets, with MSDS sheet that you need to download and do not come with the chems.
I was surprised when sampling different types, a small batch place that sells to anyone sold me a Hexavalent Dichromate that was ph .7 (yes, point7) with no information at all.
Plastic fume hoods, respirators, nitrile gloves, safety glasses and full face shields.
These chems have SOOOO many surfactants in them, they simply don't act right, they splash in illogical ways and it's easy to get things sprayed on your clothing. Best thing you can do is buy a few dozen tech books on the chemical processes and learn about how and why the chemistry works.
Folks keep asking me "what do I have to do to restore these 5 carbs."
If you had 5 engine blocks in your garage would you call Barry and say "Ok, I dunno how to machine or build engines, but tell me what I need to buy to make these into perfect, fully assembled engines. Lol.....
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Out of the Topic, but when discussion is about OEM 60 high performance Holleye color.
This is my findings to what i believe most of them looked like, just alittle more greenish than the newer goldish.