Hey all I just joined the site. I was wondering how feasible it is to swap my stock 350 out for a zz4 or something similar and still keep the tpi or at least keep it fuel injected?

My goal is to get around 350 +/- hp in this car any suggestions?

 

Welcome aboard thirdgen.org.

350 HP by what measure? The factory 245 HP rating is net flywheel HP - in other words, what the engine puts out at the flywheel as installed in the car and running the alternator & water pump. The ZZ4 is rated at 355 HP, which is gross flywheel HP - carb, velocity stack instead of air cleaner, open headers instead of exhaust manifolds with catalytic converter, dyno facility providing electrical power and electric water pump, etc.

You'll also hear references to rear wheel HP, which is measured with the vehicle on a chassis dyno and measuring what actually gets to the ground. Chassis dynos are also notoriously inaccurate and variable.

Now, back to your question: Can you put a ZZ4 under TPI and get 350 HP? Probably, if you're talking gross flywheel HP. And, that would involve replacing about every piece of factory TPI hardware, with the possible exception of the fuel rails. The ZZ4 has aluminum heads with the old '86-earlier intake mount bolt pattern, and do not have the exhaust cross over passages that feed the stock EGR valve - the good news is the '86-1/2 & up Vettes used those same heads, so if you get Vette TPI aftermarket hardware, it will fit the ZZ4 crate engine.

You could also get 350 HP out of your stock engine by working over (porting, for instance) the heads, changing the cam, and doing the same TPI aftermarket upgrades you would have to do for the ZZ4 (you just wouldn't get Vette pieces).