What V8... LS1, LT, 5.9 or 5.7 Hemi or the standard 350 from junkyard... etc...
Lot of fab work and mods to fit it, but for the most part Advanced Adapters has alot of the plates and adapters to fit it in.
You'll need new motor mounts, radiator, trans&tcase may survive but most upgrade those as well as the axles, especailly if you have the D30/D35 axles.
Do a search on here or look thru a few pages, the V8 talk on here has had numerous posts.
Why a V8 or whats the need for a V8, just curious, since I've seen a ton of posts lately about it.