What Heads for this Combo

[Big Joe]

Howdy all. So I bought a rebuilt 440 based 512 stroker short block.
It needs to run on 91 octane Cali pump swill gas and have enough vacuum for power brakes
Here’s the combo
Cam TFS 61602003 came with short block
Bore 4.350
Stroke 7.1
Crankshaft 4.25 440 Source LW
Pistons 440 Source # 5071 flat top with valve reliefs .010 below deck
It’s going in my 70 Charger that is primarily street driven. 727 trans with 3.23 gears
Any advice is greatly appreciated
Thanks all

 

[Nirvana]

Howdy all. So I bought a rebuilt 440 based 512 stroker short block.
It needs to run on 91 octane Cali pump swill gas and have enough vacuum for power brakes
Here’s the combo
Cam TFS 61602003 came with short block
Bore 4.350
Stroke 7.1
Crankshaft 4.25 440 Source LW
Pistons 440 Source # 5071 flat top with valve reliefs .010 below deck
It’s going in my 70 Charger that is primarily street driven. 727 trans with 3.23 gears
Any advice is greatly appreciated
Thanks all

Price range? If money is no object my vote is the trick flow 240’s followed by the Edelbrock rpm’s.

If you are money conscious I’d look no further than the stealth heads from 440source.

If you are cheap/poor like me, wait for Black Friday and run the speedmaster victor copies with their offset rockers and valley pan.

 

[BSB67]

Curious. Do you think we all know the cam specs for the 1,000’s of cam grinds out there, or do you think it’s everyone responsibility to go and look it up?

 

[BSB67]

I think He's gonna have a compression ratio problem unless he gets some 80+ cc heads and a thick head gasket

 

[33 IMP]

Rough wild-*** guess (not near enough info for a good guess) says 12.25 to 1, with a 75cc TFS head. You MIGHT get away with it with a very precise F.I tune and the giant camshaft, but I wouldn't bet on it. I would suggest shooting for 10.5 with that big roller (it is BIG for a street driver with no gear) so maybe the open chamber rpms, and use the head gasket thickness to get the comp ratio where you want it.
With smaller cam more suitable for a driver with 3.23s, no more than 9 to 1 on california cat piss.

 

[Curiousyellow71]

Edelbrock rpms have the biggest cc at 88. You will need it w those pistons.
Best way to get the compression down some is machine a dish in the piston, or a different piston. Next would be cometic head gaskets. 440 source has some slightly thicker then stock gaskets you can also consider.
Imo The cam being ground on 108 is going to force your hand to lower your compression some. 112 would be better. It's really not that big a cam in a 512. But you haven't really laid out your expectations?
Either way buy a good stall like a 9 1/2 from dynamic, FTI or Ptc.

 

[WileERobby]

For what you just stated, get a different cam, that one ain't gonna work well.

 

[Doorkicker]

Those are -4cc pistons (basically, just the relief volume) and even with a 88cc chamber head, which is on the large size, you're still at 11:1, which will probably ping on Cali gas and you could be getting close to detonation on hot days. I have a very similar cam, but you're going to need to do some math and checking on the piston to valve clearance, but you should be "ok"... just close, but that is very much based on what heads you get. I would definitely avoid rockers over 1.5 ratio.

Look, I'm just going to say it... you have a fairly decent short block that is built for 12-13+ to 1 compression ratio and not setup for 91 crap gas. If this is a Cali daily... you could (gulp.. I can't believe I'm about to say this) put some old stock 452 iron heads (~90cc) on it with a fat head gasket and get into the 9's and 10's on CR. But you're definitely going to have valve to piston issues, so you'll need to swap out that cam.

I'm saying all this because what that engine wants are TF270 heads, 1.6 roller rockers, a Victor Jr. intake with a Dominator on top, at a minimum. If you're not going to go that route, you might as well go super basic. Or, sell it and get an engine for daily on Cali gas.

Or, go for it and buy rocket fuel or a bunch of octane boost.

Essentially, think of it like this... you have a samurai sword to cut cheese.

No matter what you decide, you're going to need to set the fuel system up to deal with all the ethanol blends out there.

 

[lewtot184]

pump gas or race gas? pick one. if pump gas now is the time to change the pistons.

 

[33 IMP]

TF 240/270 heads, and a diet of ONLY E-85. (plus fuel system mods, and an E-85 carb). Assume about 5mpg.

 

[BSB67]

Generally agree with everyone. But, he can make what he’s got work on pump gas without replacing pistons. He just needs to pick his poison. Jack around with heads, or pistons. There is no bolt-on and go option as near as I can tell.