I have a 1987 Iroc-z It was originally a TPI. The motor blew and I am going to replace it and swap it over to a Carb. I currently have a 350 block (not the 350 that came out of the car originally. My question is would it be more cost effective to send out the motor that i have now and have it rebuilt or just buy a new motor ready to go?

It depends. Rebuilding your stock motor would be much cheaper unless too many parts aren't reusable, but won't offer near the performance of an aftermarket crate motor. If it was up to me, I'd build (or have it built) a better motor than a stock l98. It would give me the opportunity to get exactly what I wanted, and with smart shopping, done more affordably than a crate motor. If you want a real cheap idea, get a 96-2000 vortec motor and run it until it needs a rebuild.

With the 96-2000 Vortec will i have to keep it fuel injected or will i be able to still swap it over to a carb?

I would put it the other way - you can keep your TPI and don't have to switch it over to carb.

I think that i would prefer to change it over to a carb. Also i have a 700R4 Trans. The car has been sitting for a couple years. Would you think that the trans and rear are still in good working condition?

To clarify, with a 92-00 vortec motor, you can run carb or TPI. There are a lot of vortec-style carb intakes available, and there is also the SDPC/Edelbrock Vortec TPI base if that's your preference. There's always the stealth ram for the Vortecs too.

to help make up your mind go to ebay type in small block chevy with spacesjust like i typed you will find over 400 pages of parts

'96-'99 in light trucks, up to '00 in HD trucks.

Yeah, I fat fingered it. I had it right in my first post.