Head choices/engine combination

[zgeezer]

Five years ago, when I began this project, I "built" a 350 visual clone of a 300HP '70 Chevrolet.(California smog laws and all). The engine has flat top pistons, 30 over, a mild Competition Cams hydraulic lifter cam (Good for off idle to 5500, number "260" I think... over the years, I lost the cam tag.) I've acquired a '90 TPI unit and two addition set of iron heads: 1) double hump, 2.02/160 Chevrolet and 2) Dart iron eagles 72cc/215 runners. The heads on the engine are 76cc "square" chambers with 2.02/1.60. I'm committed to the FI. What would be the best choice of heads: stick with the square units, go chevrolet double hump, or jump to the iron eagles. Although I now have 2.5" rams horn exhaust, I'll go to some form of header as soon as the car is running. I'd like to go iron eagle, but every mechanic I've spoken to tells me that the ports are wayyyyyy too big, the FI will die b/4 4000 rpm and that the humps work best.

[zgeezer]

Sorry, I had a bit of a senior moment there and hit the "send" button a bit prematurely. I need some advice re: which head would work best with my combination.

 

Thanks for any comments.

[grumpyvette]

by far the best set mentioned are the 215cc iron eagle heads, the smogger heads flow about 200cfm max the double hump, 2.02/160 Chevrolet flow about 230cfm and the iron eagles about 268cfm

look here

http://www.dartheads.com/sbiron215.htm

thats potentialy an 80hp advantage for the iron eagle heads over the double hump, 2.02/160 Chevrolet and even more over the smog heads,

 

btw the mechanics your talking to are obviously talking about a stock un-ported TPI set up running a stock cam, now the cam your running now won,t work well with the EFI because the cams overlap and durration will drive the sensors crazy but if you port that TPI plenum and base and get a #114142 crane cam thats designed to work with the big heads and TPI intake it will work fine, BUT BE AWARE THERE ARE TWO POTENTIAL PROBLEMS .some year TPI intake bases have the area around the intake ports that are small enough that you might have port sealing problems with some gasket combos on those big port heads,(a swap to a T.P.I.S. BIG MOUTH BASE MANIFOLD will fix that! and that even after you port the PLENUM and BASE that TPI setup will run out of airflow at about 5500rpm so my suggestion would be to get the BIGMOUTH BASE AND a SUPER RAM PLENUM or if you really want PERFORMANCE get a HOLLEY STEALTH RAM EFI INTAKE INSTEAD

[zgeezer]

Grumpyvette, Thanks for the post. I was looking at crane, but decided that after all this time, I'd better get this thing off the rotissiere and looking like a real car. Cam change and upgrade FI will follow. Thanks.