I've been doing some archive searching and such, wondering what the best or ideal head intake runner size is for a 350 tpi engine. Seems like 200cc is the standard on 383s and 400s/406s, etc, but it varies a lot on 350s. There are a lot of stock heads as well as aftermarket arount 170ccs, but then it seems to jump to the 190cc and 195cc AFRs. Why don't I see many people running 180cc heads with TPI?

 

Because you dont really make the power to $$$ ratio running a 170, its kinda a stock replacement, the power comes in at 190, which AFR has nailed btw.


I think that edelbrock etechs or whatever they are might be 180's???


Anyways, the ideal number (if you're after power) is probalby about 190, you can run 200 on a 350, but its better suited for a carbed engine.

 

I don't think that runner volume is that critical for the typical long-runner TPI. Anything from 170cc(E-Tec) to 200cc(WP Sportsman II) can be made to work. If you concern yourself with the intake runner, look more at the contour and placement of the runner. This is the area where most aftermarket heads surpass the OEM pieces. And combustion chamber design is finally starting to play a big part in the buying decision too. The Vortec heads have a small runner(170cc) and average flow numbers, but a superior combustion chamber means they routinely make more power than some heads with bigger "on-paper" numbers.

 

where can i get the afr heads att.

 

www.airflowresearch.com

There's also various GP's if you wanna wait.