Yes I know this has been discussed but,

I know the TPI will choke the motor. So my question is, if I am producing 375 hp with a carb on my 400 ci wouldn't the gain over a 305 ci with the low power be better then running the 305? Or would it choke the motor enough that it would pull the power down to the 305 level. Don't have the money for a new intake but have the 400 ci sitting on the floor from when I used to race and the TPI is already in the car. Don't want to run the carb.

 

Assuming its an all-GM TPI manifold, you'll probably hover around 300-320hp, if you're making 375hp with a carb. Your powerband will probably end around 4200-4500 rpm.

 

This article from the June 2003 Super Chevy might give you some insight into a TPI 406.

The link below is to AFR's website where the article may be found.

http://airflowresearch.com/articles/article093/A-P1.htm

 

The 400 may very easily make 375 FWHP even with the stock TPI runners. I made over 300 RWHP on a 350 with the stock intake runners, stock plenum, stock TB, and ported stock base. Peak HP was at 5,000 rpm. The TPI is resonant bound for peak hp between 4,600 and 5,000 rpm, but its not limited to 320 hp by a long shot.

 

Here's a thread about a 403 RWHP 406ci TPI/SuperRam engine:

https://www.thirdgen.org/forums/alte...fications.html