Hello all. I am an LT1 guy and know all the ins and outs to match with the short runners of an LT1 with a cam, but I am a little rusty with the TPIs and their long runners.

My cousin has an 86 IROC w/305 TPI (auto). I am going to build a 9.5:1 comp 350 for his car using Iron heads (041s ported with 2.02/1.60 valves). The chamber is a 64cc and the piston is a flattop with valve releifs.

The intake will be a ported lower, ported plenum, 52mm T/B and ported SLP runners.

What Hydraulic (non roller) cam would be best for this car, Strret/strip? What rear gear would match it best?

We already have the exhaust and intake stuff there, so the motor will be able to breath.

Already have a 3000 stall ready as well.

Any and all advice is completely welcome.

 

I'd shoot for around 480-500 lift, 220ish duration(@.050). If you go much over about 220/230(intake/exhaust), you'll be going past the abilities of a TPI intake. We set up Dans87GTA w/ a 220/230, .497/.502 hyd roller(I know you're going flat-tappet) With .030 flat-tops, bowl blended heads, exhaust and minor intake port work he was running 13.7's with a stock tune. Car sounds strong and pulls good to around 5200.

 

What kind of exhaust closing point seems to work best? 9 ATDC with an intake opening 6 BTDC? I seen a cam with 230 .050 simular to this , the overlap is in the 30 degree range.

How much is too much overlap for a TPI tha't not really worked?

Thanks for the advice.

 

For a street/strip motor, I woudn't get to caught up on the over lap. Mainly, you need to go in around a 112 centerline. 112+ seems to work best w/ efi.

 

Thanks! I 'll keep an eye for that 112 then, seen many with that I would like to try.