Hey guys, I would like to know what heads I should run on the engine I'm buying.

1974 350 (.30 over)

Speed Pro forged flat top pistons
Lunati mechanical solid lift cam (flat tappet)
507"/519"dur@.050 249/259(3200-6800)
Competition double roller
1.52 aluminum roller rockers
Performer RPM intake
750 Speed Demon w/mechanical secondaries
Reconditioned rods w/arp rod bolts
High performance HEI distributor
8.5mm MSD wires
Headers? Thinking 1 5/8 Hedman long tubes

Valve springs in the Iron Eagles are only good to .525", am I good or is it a little to close with the .519" lift cam? Finally what kind of power should I be putting out? Thanks for any help.

 

Anybody?

 

I would say the 200s, judging by the cam you look to be running this thing at high RPMs.

 

You'll be wanting the smaller 64cc chamber versions of the Iron Eagles to get compression up in the high 9s/low 10s for use with that BIG cam. In this case, definitely the larger 200cc intake ports to match the rest of the combo.

I think I'd check with the guys at Dart about the spring package you choose. I think they have a package for solid lifter flat tappets that will take .550-.580" lift, if memory serves.

 

For one I would get a smaller cam, or a bigger intake. I'd lean towards a smaller cam seeing as how you're looking at Iron Eagle heads. Not a bad head at all, just they wont support a big cam/intake combo. Not to mention an RPM intake wont support that cam that wont make power until the top of the intakes range. Look into comps 236/242 grind, may still be a little on the big side for a 350 ci motor, but it'll work better with that intake.

That combo you've got in your head is a mess, everything needs to be matched so it works together.

I would go with an Air Gap intake, 650dp carb, the 180cc heads and a cam in the high 220's to low 230's with around 10-10.5:1 compression. It'll make plenty of torque down low and be more streetable.

 

Thanks for the replys guys but I have decided not to buy the engine and probably going to sell the thirdgen and just save up some more money so I can do everything right. If I bought that engine it was going to be basically all my money. My buddy had the engine in his S-10 and it ran just fine, he had AFR 180cc heads though, it ran 11.60s on motor and 10.80 on a 150 shot so I was thinking low 12s with the Darts. Thanks for the advice anyways though.

 

Use the 200s, you'll be much happier with them. You might even be able to use heads even bigger than that, but the 200s would work great with that setup.