67 Fairlane GTA 390 Headers

[JamesonRacing]

I have the flowmaster tailpipes on my street Fairlane and really like the look and the fit.  They are full mandrel-bent tubing over the axle, then have 3" polished stainless slant tips.  You can see them in this video:

http://www.youtube.com/watch?v=IL7518PBM64&feature=g-upl

The mufflers are Dynomax Ultraflow 3", but they was too much resonance so I added two Spintech mufflers ahead of the Dynomax to tone it down.   The Flowmaster should be good to go as delivered.

[amdscooter]

^^^ I watched your video a few days ago.. nice ride! 

[My427stang]

I really do not like Flowmaster mufflers, they resonate in the interior and in many cases have been proven to lose power over even quieter mufflers.

With that being said, mine with Flowmaster 50 series used to soud really good OUTSIDE the car, inside the car they had a booming noise at steady cruise that made it unbearable. 

Here is my 489 with the Flows



Here is my car after with Borla ProXS no other changes, a little different outside, but inside is amazing, nice growl but no booming



Here are the same Flowmasters on my low compression 397 truck

No tailpipes, although since then I have put 3 inch tailpipes coming out under the rear bumper



My guess is I wont like the Flowmasters with the upcoming 445, although I will try them

I'd recommend as much mandrel bending as you can afford, and then use a Dynomax Ultraflow, Borla ProXS or Magnaflow muffler, they flow well and do not bounce the exhaust around in the can, causing the resonance like a Flowmaster

[amdscooter]

Thanks very much for the information My427stang. I really like the "stance" of your Mustang! Just about as good as it gets for a street rod IMHO. My last two vintage big block cars (this 67 and a 70 Dodge Charger 500 383cid) had classic glasspacks slapped onto the stock exhaust. I don't like a lot of interior resonance on long drives either. Which of the manufacturer's you listed ( Dynomax Ultraflow, Borla ProXS or Magnaflow) do you feel would do the best job keeping the interior resonance to a minimum? The muffler shop I'm using has been recommended by the local Shelby club. Spoke to the owner, nice guy. His current project is a Galaxy ragtop/427 mid riser. He was kinda busy when I stopped by for the quote so I'll probably stop by again before I get the headers on and ask him for advise as well. So far I'm planning 2.5" out to the rear bumper. The muffler shop says 2.25" is a lot easier for my application and he'd cut the price $100 if I go that route. Would I notice a difference?

Few other questions for the horde. Header paint or buy the ceramic coating? I have ordered the bare headers with plans to "rattle can" some sort of heat resistant coating onto them. Been wrestling with that decision the last few days. This is a CA car so we don't get the really bad snow/salt/rust issues here. I'm sure I could call Stan and have him add the ceramic coating, It's an extra $225. Worth it or no?

Lastly (well for this post anyway  ), my 390FE is a California car that came smog equipped. I've removed the air pump, thermactor(sp?) and all the rest of the smog gear and plumbing except the air injector tubes. Luckily the check valves still work but those bars sure look wonky all by themselves. I'm thinking that this would be a good time to finally rid myself of those. Any suggestions as to what I should use to plug the holes in the heads? I was thinking of using brass hex plugs but I'm open to suggestions.

Thanks!

[My427stang]

I like my ProXS, but all three of the absorption mufflers will kill resonance, so you cant go wrong.  I just havent used the others.  I think the Magnaflows probably flow the most but may be slightly louder outside the car.

I personally wouldn't go under 2.5 inch, but if you are going to remain stock or near to it, the 2.25 will probably make it, depends on your motor if you'd notice it. 

For a reference, my mild 397 in the truck was noticeably different when I went from 2.25 crush bent/glasspacks to 3.0 mandrel bent/Flowmasters.  The crush bending really hurts, especially as you get to small diameters. 

If you think this motor will get stronger later, you'll have to pay twice, so in my opinion, go with 2.50 now.

As far as ceramic coating, if you can afford it, do it, it makes a HELL of a difference for underhood and floor temps, plus they stay pretty almost forever and they are easy to sell later.  I wouldn't build one without ceramic coating now, but admittedly I built a bunch with standard rattle can when the budget wouldn't allow.

[amdscooter]

^^^ Thanks so much for that. I'm going to give Stan a call and have him put the coating on. As far as the 2.5 vs. 2.25, I'll go with the 2.5 as per your recommendation. I'm not planning on a massive HP/Torque ride here. Perhaps a mild cam, aluminum intake and larger carburetor over the winter.. but that's about it. If and when the motor needs a rebuild (76k original and still strong) I'll probably go with a medium stroker rebuild. Hopefully the 2.5 will still be adequate. I'll look into the Magnaflows as I'm not horribly worried about noise outside the car. Thanks again for all your input. 

[66FAIRLANE]

X2 on the ceramic. Wouldn't have a set without now.

[jayb]

X3 on ceramic coating.  For under hood temps alone it is well worth the price.

[drdano]

Any suggestions as to what I should use to plug the holes in the heads? I was thinking of using brass hex plugs but I'm open to suggestions.

Any of the FE parts shops will have plugs for these.  Survival, Precision Oil Pumps, Blue Oval Performance, etc.

[amdscooter]

^^^Can anyone verify the thread pitch? I've read a 1/2-20x5/8 allen setscrew will fit flush. Would I have any issues using the setscrew with the tapered bore?

[amdscooter]

Answered my own question about the air injector. I had pulled one off a 390 T-Bird in the bone yard some time back and found it last weekend. The threads are indeed 1/2-20. Ordered some blackox setscrews to fit. My FPA ceramic coated headers should arrive first week of Sept so I'm trying to prep for the installation. Thinking I might wanna start a new thread as this one is starting to creep and I have a few more questions. If the mods feel I should start a new thread feel free to let me know. Onto the bonus round.

Motor Mount fun
I was crawling around under the Fairlane yesterday and noticed the motor mounts are looking not-so-good.. not in half yet but pretty sad shape. The driver side was missing one of the 3 bolts on the block side. I ordered some new mounts today and I'll be replacing all the hardware with grade 8 bolts when I do the swap. Anyone know off the top of their head what size the three bolts on the block side are? Maybe 1/2-13? I cannot get a bolt in there to test as the hole is currently a little out of alignment and I don't want to take one of the two remaining out. I'd like to have the hardware in hand before I pull the old parts. Here is a pic of the missing bolt whose size I'm looking for:



More on motor mounts. I'd like to modify the new mounts, I believe it's called "pinning"? Drill two through holes, countersink one side and install bolts through the entire setup nutting the backside as illustrated in these pics.:





My question is with the countersunk side facing the frame landing flush, is there space on the block mounting side for the retaining nuts?



This example I found they welded the nuts on so they to not come off after the weight of the block compresses the rubber. I'd probably use Loctite or drill holes in the nuts for some safety wire. The mounts on my 390 are nearly flat and I cannot tell if there is any space at all on the block side. I'd love to do this mod but would hate to run into interference issues. The different pics of my C6ME-A block online are not very conclusive. Any ideas how much space I have to work with on the block side?

Cam recommendations~intake
I'm going to have to pull my radiator (more on that later) and I'm thinking as long as I'm in there I might replace the stock cam to help the FE breathe a bit easier. My 390 is an "H" code/2V.. low compression (9.5:1) that came with a 2 barrel carb... yay pump gas!  I'm not planning any lower end work any time soon if I can avoid it so it's staying 9.5:1 for the time being. Anyway, I'd love to get a better CAM that I can install without having to make changes to the existing valve train (rockers, rods, springs, etc.). I'm not looking to give the Fairlane a sound like it's got a huge rock crusher in it. Just like to increase performance a hair and perhaps get better mileage outta it. I have C7AE-A heads if that helps at all. I've heard the Comp 268H is a good candidate for a painless swap out. Good.. bad.. hell no.. something better? Totally at the mercy of your collective expertise here. Also.. is there an off the shelf~bolt on intake I can lay hands on for a few hundred bucks that is worth the investment over the stock/cast iron dual plane? Stock has to come off to get at the lifters if I replace the cam.. long as I'm in there right? 

Fan fun
Not sure if it's because my Fairlane has past damage to the front clip but for some reason replacement radiators do not fit well in front of my fan clutch. The current rad that came with the car when I got it is a 3 core just a "C" hair over 2" thick and has maybe 1/4" clearance from the fan clutch. I bought a supposed exact copy from Autocrafters last summer, it's about 3" thick and will not fit with my fan clutch installed. I have not been able to locate a shorter fan clutch for my application anywhere. I tried the new radiator with a pair of 10" thermostatically controlled fans but they could not keep up and temps got over 210F earlier this summer. I pulled the new rad.. had a quick repair done to the old rad and stuffed it back in. Now that repair is starting to leak again and the radiator shop guy says it's time to recore, he won't quick repair it again. I still have the "new" radiator and am thinking of using it again minus a clutch with a Flex-a-lite high performance flex fan on a solid adapter cut to proper length. Is this going to cause me issues with the fan running 100% engine RPM? I know I'll lose some mileage/power and probably gain some noise but I'm currently out of cost effective options. 


Thanks in advance

[JamesonRacing]

Replacing the motor mounts while you're installing the headers is a great idea.  I'm using stock motor mounts on my street engine with no issues, haven't heard of anyone having problems with them until they get old and cracked.  Adding a bolt through the mounts kinda defeats the isolation properties of the rubber mount, so you may feel more noise and vibration in the car.  On race cars you'll often see a cable, chain, or strap on the driver's side front corner of the engine to limit engine flex, but not necessary on a street car.

The Comp 268 should be a decent fit, you may go a bit more aggressive without losing a decent idle.  I'm gunshy of flat-faced lifters these days, so I'd personally save up my pennies and go to a hydraulic roller cam...Barry has a large catalog of grinds that would wake up your 390.

[amdscooter]

^^^ The theory behind the bolt thru on the motor mount is to just barely tighten the bolts. This way when the block is sitting on the mount the rubber will compress and it will work just like a traditional mount under normal loads. When you roll on the throttle hard the slack in the bolt is taken up and it prevents the rubber from taking all the torque just as a cable or chain would. I'm really interested in this mod as it's so easy to do on the mount itself. I just want to make sure I have the space needed for the nut on the block side before I get to drilling holes.

Far as the cam goes.. I'm sure a good roller setup would be nice eventually but time and budget are not allowing for a lot of head work right now unless it becomes absolutely necessary. I chose the Comp 268H as it will help the breathing a bit and if I'm reading correctly I won't have to worry much about the impact to the stock springs, rockers and rods.

Thanks for the input. 

[chris_r]

I have used comp xe262 cam in stock 390 with 9.5 to 1 cr. The best cam i have ever used in a stock 390 very very strong from 1000 rpm to 5000. O i used edel streetmaster intake holley 750 and tri y headers. It would really put you back in the seat for what is was. Great tq

[hotrodfeguy]

CAM I would run Lunati 10330206

The nuts, we always ran a metal lock nut so we could leave a little slack in the bolt as previously mentioned for the rubber to get the preload.