Im not new to the thirdgens nor moding. I have a 96ss camaro, and prior to that ive had a 89 formula tbi which i moded to death and did my own dyi-proming. Anyway to point at hand I recently bought my girlfriend my friends 88 Iroc which has been moded pretty decently. Has 5k on the rebuilt engine which is a 355 10:25.1 flat top pistons running .015 head gaskets on rebuilt 081's which im assuming had a valve job of some sort, 1.6rrs, edelbrock headers, blah blah blah blah. He gave me the last dyno sheet from the last time he dyoned. Which netted 230hp/393tq. Not to shabby i thought, but the power drops off hard @ 4600rpm which is the case for most stock TPI setups. This is one of them. I was wondering if adding the HSR would net me the 20-30 advertised hp holley says. Also I do not plan on swaping cams or redoing the heads. Its pretty decent in the fourm its in. Runs a 13.7 n/a and a 12.6 with a 100shot.

 

It likely does give the advertised HP but you loose quite a bit of torque.

I ran 89mph with the TPI. I ran 89-90MPH with the Stealth ram. Felt alot beter in the top end.. but obviously didnt do anything for ET's on a stock engine. HSR ports are 1205 and stock heads arnt. Likely creates lots of turbulance. I'm running the HSR on my current engine and its running 98mph untuned at 1500feet with crappy air and no tuning.

If you have the heads and cam that will breath to 5500+ then it might help. Otherwise... It did nothing for me on my stock engine.

 

Thanx bro. Im not looking to lose the torque. Guess ill just siamese everything

 

double post...lol

 

For your combination, I'd gasket match and do mild porting on the base (not siamese), pick up a set of newer SLP runners (since the older ones have one set of runners on each side fully siamesed), knock the divider down to about the half way point, and hog out the plenum. Any more siamesing than that on a TPI system being used on a 350 with less than 240cfm head flow at cam lift,,,, you'll give up more torque than you can make up in horsepower. Unless you want to run 3.73 plus gears and more than 3000 rpm worth of stall.

 

Actually I am running 373s gears and my stall flashes to 2900. but its a 2600 stall