So i have been into quite a bit of bad luck lately. I recently bought a 89 Camaro with an LT1 conversion already in and running...sorta. So i pulled the motor and started a complete tare down and re-build. While the block was at the machine shop they found 3 cracks in the lifter valley. So now here I am with everything I need but my LT1 block. I found one almost 3 hours away but would need to get it checked before i bought another one. So I have kinda decided about going back to TPI which is what my 89 Iroc came with. I have a 350 Gen I that was given to me for free (love the price). I would rebuild that motor with the LT1 cam and put higher performance rotating assembly in and probably some heads. But, I have read everywhere that the stock TPI doesn't flow very well and can barley achieve 350HP with out spending a load of money on ported runners/baseplate/plenum. So is putting all this money into this 350 then slapping this TPI intake on it really worth it? or it is it going to choke the hell out of my engine? I was thinking about just going carb too... But i love the TPI and LT1 setups.

 

Stock TPI can make power although less than other intakes and over a smaller rpm range. Comp cam did intake comparison on a 383. Stock TPI made 400 hp and 500 ftlbs versus 460 hp and 534 ftlbs with TPIS big mouth setup.
http://www.compcams.com/Community/Ar...?ID=1737510521

That being said you are correct that stock TPI would be restrictive on a 350. Chevy only designed it for 305. Mid to high 300's hp would be possible with aftermarket runners and base (or ported stock base). Another option is the FIRST TPI intake that is large enough stock to support lots of power. Whole intake is $1,000 though.

Not sure what you have done to car but going past 300-350 hp will require transmission and rear end upgrade or replacement. You could settle for slightly modded TPI intake, decent heads and cam for good power (350 hp, 400ftlbs ?). I guess it depends on how much you want to stick with TPI and amount of money to spend. I also think LT1 cam will not be enough for 450hp engine.

Maybe some people with strong TPI setups can chime in. You can then see what kinds of power they are putting down. If you are not a 1/4 mile junkie, a strong TPI setup might be fine for you.

You can also add an LT1 intake onto TPI based engine. Requires some modification but $$ would not be too bad since you have both engine types.
https://www.thirdgen.org/forums/alte...ntake-com.html
http://sethirdgen.org/LT1.htm