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Discussion Starter · #1 ·
Hello, I’m new here seems like an awesome page.

I have a 92 lx with 331 stroker, GT40 polished and forged heads, BBK headers, mech roller cams demon 650 carb, roller rocker arms, PA racing trans super competition(1,000 HP), C4 tranny, stall is 3,000 CFN for NOS. Headers, runs on pump gas, much more..nitrous,
I have 4.10s in here, with be cool big aluminum radiator. Yes also with Keith black pistons, ferrea valves, , (just ordered the aluminum heads). She sounds mean as hell. Scat steel crank.

What would you guys say instead of my GT40 heads? Or what else could I do to this?
Also how much HP would you guys say I’m pushing?
 

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Discussion Starter · #2 ·
Hello, I’m new here seems like an awesome page.

I have a 92 lx with 331 stroker, GT40 polished and forged heads, BBK headers, mech roller cams demon 650 carb, roller rocker arms, PA racing trans super competition(1,000 HP), C4 tranny, stall is 3,000 CFN for NOS. Headers, runs on pump gas, much more..nitrous,
I have 4.10s in here, with be cool big aluminum radiator. Yes also with Keith black pistons, ferrea valves, , (just ordered the aluminum heads). She sounds mean as hell. Scat steel crank.

What would you guys say instead of my GT40 heads? Or what else could I do to this?
Also how much HP would you guys say I’m pushing?
Hello, I’m new here seems like an awesome page.

I have a 92 lx with 331 stroker, GT40 polished and forged heads, BBK headers, mech roller cams demon 650 carb, roller rocker arms, PA racing trans super competition(1,000 HP), C4 tranny, stall is 3,000 CFN for NOS. Headers, runs on pump gas, much more..nitrous,
I have 4.10s in here, with be cool big aluminum radiator. Yes also with Keith black pistons, ferrea valves, , (just ordered the aluminum heads). She sounds mean as hell. Scat steel crank.

What would you guys say instead of my GT40 heads? Or what else could I do to this?
Also how much HP would you guys say I’m pushing?
also polished hurricane intake
 

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flow numbers @ .5 lift
intake around 190 cfm and a bit
exhaust side less than 140 cfm
so building 380 hp with a bigger camshaft and 6-8º split is possible with all the good parts.

AFR 185 cc heads
275 cfm intake @ .5"
210 cfm exhaust @ .5"
easier to make 500 hp with the AFRs than 375 with the gt40 heads
 

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Depends on the cam and pistons in terms of crown shape and attention to the build details.

It’s nice to buy name parts at high prices nothing bad about that, but big name parts alone do not assure a maximized output. One can build a 400 plus horse engine on Ebay parts and it will stay together.

The big advantage to aluminum head’s compared to GTP iron head’s is you can take, in fact must, of their thermal characteristics to hold off the detonation threshold. This means running more compression and operating the block and head’s hotter. Here the trick is to push operating temp up while getting induction temp down, to this end and taking advantage of aluminum’s thermal characteristics is to run an air gap intake to get the charge temp down. A totally cool trick is to run head’s with no exhaust heat crossover with an intake with the exhaust heat cross over passages, then drill and tap for water fittings than pump cold water through the under plenum passage using a small 12 volt pump, external exclusive radiator or ice water cooler.

A problem with aluminum head’s is the dimension build up between piston crown and the squish/quench step of the combustion chamber here you want this .035 to .040 inch which usually means gasket selection issues unless to zero deck the block or use tall compression height pistons. Flat tops are best followed by D or stepped dishes. This gets into consideration of a larger chamber to dial in the compression.

The SBF tends to suffer from undersized valves and ports so most any aftermarket head really wakes these motors up, even the ProComp head is an immediate power provider.

Power is where the RPMs are and that pushes a more robust valve train. Here it means 7/16th studs or shaft rockers. Lots of guys immediately reach for stiffer valve springs while retaining wobbly 3/8ths studs and end up with little if any improvement. The first trick if you’re going to wind out over 5500 is to stiffen up the pushrods and rockers.

So assembly dimensions are as if not more important than big name parts.

Bogie
 

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That's a pretty potent little combination, especially if you were to go to an aluminum head that flows in the 250+cfm range.
Pretty stout cam in a 331" engine, probably peak power somewhere near 6800 rpm with a 7000+ rpm shift point with good heads.
I'd say around 480hp with the 250 cfm head, 500hp with a head that flows 275 cfm.

ProMaxx Maxx Series 180cc would get you real close to 500hp for a budget head.

ProFiler All American for a good head....but it might be too big at 205cc port volume.

Trick Flow also has some very good Ford Windsor heads. AFR is good.

The GT-40's are going to chop 100 hp off that...if not more like 120

Put good heads on it and it'll be a ripper.
 
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