im looking at a 350 from a 84 vette c/f inj. will this work in my 85 iroc w/ all of my tpi stuff installed?

Yes, but you may need to change the oil pan/oil pump, and most likely the front accessories.

is it worth installing as a temp while i build a motor? what kind of performance did those things come with?

A mind-numbing 205 HP with the cross-fire.

(At least it was faster than the '83 Vette. . . )

would that # change if i use my heads and tpi off my blown engine?

It would probably be improved with cam and TPI alone. Not sure about the heads; if it's just temporary, I don't think I'd bother.

lol good one....i wonder how many people will miss that....ok u shouldnt have to change the oil pump and pan... ive swapped a cpl 80s model vette engines into third gens and never had an oil pan/pump fitment problem... 5.7 kid is right bout the accesories though for sure, but just use the ones u have. your tpi stuff will bolt up but im assuming your tpi is a 5.0 if so youll need to get the bigger injectors and everything else tha goes with swappin to a 5.7....hope that helps....

No personal experience with Vette engines, just what's been said on this Board about Vette TPI engines. I don't know if that means all C4, or just TPI. I would guess C4, which is why I mentioned it (and put the caveat on it).