Engine Swap

I have an 86 chevy 4x4 with a tired 305 & am looking to upgrade to a 350. I stumbled upon a great deal on 88 350. How easy is it to convert an 88 to work with my 86? Or am I better off getting the right block and just rebuilding it. I want to scrap the fuel injection and just run a carburetor and the truck is going to be a lightly used on/off rd vehicle.

Thanks
Mark