ok. I've got a '78 Chevy 1/2ton 4wd. with a 4speed. Oringinally there was a 350 in it and i'm wanting to swap it with a 6.2L Diesel. My guestion is, will the diesel bolt up. Also will a brake booster fit on that year?

A hydroboost setup should bolt up where the vacum booster use to be. My 78 1 ton 454 2wd has a hydroboost setup and all the diesels I've seen had them so it shouldn't be that hard to find the setup you need for a diesel conver.