428cj heads $worth$

[ScotiaFE]

I'd keep the RPM, although the Streetmaster is kool.
When putting an intake on an FE you should always assume that it may need a small cut on the sides or bottom to fit right.
With the old blocks and heads being worked on over the last 50 years chances are somewhere along the path
someone did some cutting to the block or heads or intake.
Tough call on the CJ's over the C4's. Although the CJ's are little rough they are still usable, a fresh skim won't hurt them.
And when you open the hood you say "oh ya it's got real Cobra Jet heads".
That alone is bling points.

I agree with Jay. Pull out $600 and he may bit. lol

[Heo]

That cylinder have been standing with
wather in it for a wile the pitting is not
a big problem. But what about the valve
seats? Hard to tell from a photo but
i think those valves look deeply resesed
like in grinding the seats alot.
You loose a lot of lift there since the
valve dont start to flow much before
its over the roof of the combustion chamber

[fe66comet]

When I was at the cylinder head crossroad I figured the cost of the used head, hardened seats, new guides and three angle valve job. Then the cost of swirl polish reduced stem stainless valves and came up way over the cost of the Edelbrock RPM which flows better than the medium riser anyhow.

[galaxastang]

Looks like I'm leaning more torwards the C4's. Those seats do look recessed, I have nothing to compare them to. I was told they were rebuilt from stock and never touched before.  I don't have the money for edel rpm's, but read there not that much better than the cj's other than weight loss.

[fe66comet]

Yes the stock heads are heavy as hell. Another reason I went aluminum and if you intend on port work you will have to do it yourself as the noobs in the industry only do aluminium and most only know how to enter a program and have no concept of how to make a head flow. Depending on the age the heads also might have iron seats and will have to be machined to accept hardened ones to run unleaded fuel with the lack of cooling and lubrication lead offers. Another factor is guides, if they are 50 years old and have been rebuilt even once they will be knurled so your stem center to seat alignment will be all jacked up and knurled guide are just a ban aide only as your surface area is reduced to a bolt thread and the material has been reshape resulting in a soft metal and tends to break off.

[galaxastang]

No porting, just trying to wake up the 390, with a good set of heads and the cam I have. Plus a few other goodies as stated earlier. Right now I want to find a good set and these cj's might not be it. The C4's will have new guides, hardened seats, cj valves, 600 lift springs etc. So maybe thats the route I should take.

I know it's not a very good pic, but any one else think the valve seats may be sunk?

[fe66comet]

Well if you can actually gain access to them measure the stem height from the spring seat that tells the whole story.

[galaxastang]

I will try and do so, what kind of measurement am I looking to find or does it vary? I guess I'll have to look up some cj head specs to compare. I read laying a straight edge across all of the valve stem tips can get you rough idea, because intake valves don't recede like the exhaust. True, false, myth, wives tail?

[Heo]

A straight edge is a good start then you see if
the valves is at same height
Most times the seats are only grinded as much as
it takes to clean them up and if some are grinded
much the valve is higher than the other
Back in the stoneage when i was young there
was almost impossible to find a set of CJ heads
in Sweden and the story was that the C4 heads
was equal to the CJ heads if you changed valves
I dont know if its true
If you are low on money and the C4 heads are
cheaper have new valves, seats,guides.....
and its well made i would buy them and just
clean up the ports from flaws but im no expert

[fe66comet]

The actual.specs Jay would know I am kinda out of the game now and haven't done a valve job in a very long time. The specs will read from the top of the keeper groove to the spring seat. This takes out the equation of having the vale tipped.The seats themselves should not be recessed and.the valve should extend above into the chamber both intake.and exhaust. The reason some might say the exhaust is lower in the chamber I would guess is the fact that the exhaust wears quicker and erodes faster both on seat and valve face but both should be the same height new.

[galaxastang]

Got an appointment to go inspect the heads Tuesday. I spoke to him of my concerns and he said he'll work with me on price. We'll see how it goes.   Anyone else have thoughts on rpm vs streetmaster? Thanks

[jayb]

The Performer RPM has more "bandwidth", so to speak, than the Streetmaster does.  Depends on what you are going to do with it.  They are very, very close to the same in performance from 350 - 450 HP.  Over that number I would give the advantage to the Performer RPM; that manifold performs really well all the way up to 600 HP or so.

[galaxastang]

           Well, I went and checked out the heads yesterday. We talked cars, had a few beers and after expressing my concerns about the water damage and valve seats, I offered him $500 and to my surprise he shook my hand and said deal! After getting a better look at them the water damage is minor and should clean up fine. I ran them over to the speed shop I deal with and they said the valve seats are also in good shape. I left the heads with them for a once over and to replace the springs with ones that match the cam.
               
So with that, I have
.30 over 390
C80E-6090-N cj heads
swapping the performer with a rpm intake or maybe streetmaster?
keep the 670 street avenger or go with 750 vac. secondaries?
Looking at Sanderson shorty headers,  only ones I can afford right now, are they any good? any other suggestions?
I have a pertrinox elec. distributor, someone mentioned advaned curve of 36 total mechanical, any thoughts?
Cam: Summit Racing Part Number: LUN-00054LK
UPC: 090127463864 Cam Style: Hydraulic flat tappet Basic Operating RPM Range: 1,500-5,000 Intake Duration at 050 inch Lift: 230 Exhaust Duration at 050 inch Lift: 230 Duration at 050 inch Lift: 230 int./230 exh. Advertised Intake Duration: 292 Advertised Exhaust Duration: 292 Advertised Duration: 292 int./292 exh. Intake Valve Lift with Factory Rocker Arm Ratio: 0.554 in. Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.554 in. Valve Lift with Factory Rocker Arm Ratio: 0.554 int./0.554 exh. Lobe Separation (degrees): 109 Computer-Controlled Compatible: No Lifters Included: Yes Lifter Style: Hydraulic flat tappet

Should I keep the stock  non adjustable rockers and get a set of end stands or go with adjustable?


I have a spare 9" with detroit locker & 4:11's I may swap in also.
Looking to wake her up and have some fun on the street! 
Well I guess that's it, any and all advice and info is greatly appreciated.  THANKS  Guys

[ScotiaFE]

Sounds like a great plan.
I have basically the same combo in my green Fairlane. I have a Crane stick probably around those numbers or so.
It's been a while since I seen the card on it. lol
I have a old stock single dizzy (with oil cup...lol) convert to a pertronix and have 36* total mechanical, 12* initial.
I'd say your at the limit with stock non adjustables, adjustables are just that, adjustable.
The 670 may be tad small for WOT blasts, but for now it should do. Up grade as money dictates.
I run 3.25 gears with a wide ratio TL and all most always run on the highway.
4.11's will get you out of the hole fast, but you have to spin so fast to stay up with traffic (75 mph/120 kph) on the highway it's not fun.
I be dammed if all the Kia's and Hyundai's are going to pass me.
Just something to keep in mind if you plan a road trip.

[galaxastang]

Thanks Scotiafe,
          I have a line on a good set of factory adj rockers and end stands for cheap.Not planning on any road trips, but I figured I'd rebuild my current 9" with 3:50 gears when it's out just in case I get the itch to roll to the shore.