[dsraven]

agreed, if the engine needs a bunch of money spent then i would simply button it up with lube etc for storage, pallet it as a complete drop back in type deal, and then (if it were me) I would install an LS engine. that will take some cash and other stuff would need to be changed too, so the small block would be the cheaper option. you could fuel inject it though so it would be a better runner and easier on gas. maybe think about getting that gas tank out of the cab and also a dual master cylinder for the brakes. if you go small block you could also swap the rear axle (also pallet the old stuff as a complete set up) with something that would give you a better highway speed or go with an automatic that has overdrive. again, more changes. whatever you do, keep the old stuff and be careful with taking it apart because one day, when you wanna sell it, that would be a great thing to have in the portfolio.
swapping in a v* with the original driveline would require a different bell housing for the V8 engine with the rear cross ember mounts like the old 6 has. you can buy new or used. then some motor mounts, exhaust manifolds and a system behind them, rad hoses, etc etc.