Both are TBI units and they look identical. My Dads Blazer caught on fire a few years back. And The 350 is perfect shape, He always changed the oil. and took great care of it. Im Trying to Get him to give it to me. Seeing how it would Fit right in to my Camaro. Other then a wiring harness What else would i need for the successful swap?

I don't think you need a wiring harness at all. It should just be a straight-forward swap. You shouldn't need anything different at all.

Good luck!

You will need an ecm prom for the 350 as well, or your motor may throw codes.

Maybe an oddball sensor or two off of your old motor, and a knock sensor for a 350. You'll know more when you get into it.