I've got a stock '88 iroc with an L98 and 700r4. I would like to get around 350-400hp out of it and remain emissions legal (I live in California). What head and cam combination do you guys recomend? How much power can you make using the stock tpi intake before using and intake and runners?

 

i have the same question except i'd like 400-450 hp and i already have upgraded intake manifold and runners

 

to make about 350 crank horsepower, i'd recommend upgrading your runners and base and port matching it all together as well as to the plenum. fully ported out SLP runners seem to work very well. else get the big tubes from TPIS or

as far as a heads and cam and still remain emissions legal, i'd go AFR or trick flow smog legal heads. they flow really good. you might wanna look at the AFR 180 cc heads as they seem to work well with TPI while the 195's do abit better with higher rpm applications like with superam, or HSR. Cams, i'd look at ZZ9 cam from TPIS.. several board members on this site have that cam and make near 300whp. anything else simlar to it, like the LPE 213 cam or the LPE 219/219 cam but make sure your heads flow well on the exhaust side so you can benefit from the single pattern. Another cam u might want to try is the new comp cams XFI series.. with duration 218/224. its a nice fuel injection grind with 113 LSA so it will stay fuel injection friendly as well as emissions friendly. i plan on going 383 with the XFI 230/236 cam with HSR. not emissions legal but 450hp

superam intake and runners will give you the best performance but its a pain in the *** to install and expensive. used you can get them for same price as upgraded TPI so snag it if you can... make sure its complete tho. as long as u take your time with it and research about the install, you can make the install go somewhat smoothly. a LPE 219 and superam on AFR 195's or similar heads is a HOT proven low 12 second combo. thats near 400hp on crank EASY.

for 400-450 hp and TPI, i find it harder to pull off. one member on this board i know of has made 330rwhp which is closer to 400crank hp with his super ported out SLP runners and ZZ9 cam i believe. thats the best i seen. i also seen another one making ove 300whp with a big cam that i wouldnt have thought to run in TPI. but if the tune is right, it works. 400-450 hp is better suited to either a 383 TPI or 350+ inch motor with holley stealth ram, super ram, or mini ram intakes

 

What kind of idle quality does the ZZ9 tpis cam have? Some camshafts that work well in tpi applications don't pull enough vaccum and get busted by the smog police. I have also heard some good things about edlebrock's cylinder heads. Does any body have any experiences with these cylinder heads?

 

I have used the ZZ9 cam on a 350 with stock heads and 1.6 rockers and had a very smooth idle with good vacume.

 

The ZZ9 cam has excellant idle properties. With a good tuner it is almost like stock.