[MARKDTN]

'80s crate is likely 2-piece seal, flat tappet cam and 4-bolt mains. I'd dump that and get a later 1-piece core to build-maybe a '96-99 Vortec so you get those heads. Roller cam is the way to go. 2 bolt or 4 bolt makes no difference on a stockish engine. I like EFI but a carb is OK.

Bear in mind that a 700R4 has a very deep 1st gear so 3.08 may be fine for a rear ratio. I have a 700R4 in a car with 3.7 rear gears and first gear is useless. Wish I had left it 3.36. I would definitely try it before you change rear ends. My '83 K20 has 700R4 and 3.42 and it is a very good match IMHO.