I ended up giving the blazer to a friend but it's been riding rough and he wants to basically restore it. I was wondering how easy it is to replace the throttle body injection 4.3 with a newer 4.3 vortec. Is it bolt in pretty much?

 

You would need the computer, wiring harness, fuel pump and lines, and probably some other stuff I'm forgetting about. If he just wants more power, it would probably be easier to swap it for a TBI 5.7 V8.