Hey guys im the proud owner of an 87 iroc and need some help.What is the best way tofine tune the TPIfor a bigger horse power gains? Bigger Nozzels? Any info is a help thanks in advance

 

I don't know what you mean by nozzles but the L98 engine is notorious for having a crappy exhaust manifold and an intake manifold designed for low end torque only (severely limiting high end power). If you want to get gains, I would go with headers of some kind (Long tube equal length preferably, but any kind will beat stock) and a new intake manifold. Also a cat back with mandrel bends will give some decent gain as well.