looking into a new engine for my '88 formula 350. just wanted to know what different people were running with a gm tpi system, modded or stock. i would love a ZZ430 clone or the fastburn 385. shooting for over 400 hp with reliablilty and decent economy (not a must) . already have tremec t-56. also looking at ls-1 swap. any suggestions would be great thanks.

 

Go LS1...
An LS6 intake and headers and exhaust on an otherwise stock LS1 and you have over 400 hp at the flywheel.

TPI will help you get high torque numbers, but hp at 400 is unheard of unless you go with other fuel injection intake manifold systems.

Considered the Ram Jet 350?
SDPC offers TPI crate engines...
Lingenfelter might be too expensive...
TPIS offers high hp fuel injected crate engines...

 

You'd need to do so much work to the TPI system to get to 400hp! TPI is really torque focused, so if you are fixed on long tube runner it'll be expensive. However - as said many many times you can keep the tuned port but ditch the induction setup and go with an assortment of better breathing setups - HSR LT1 Superram or Miniram - all will easily get 400HP with right setup.