63-72 are direct fit. Coil or leaf.
70 and up will be 1.5” wider but that’s not a problem.
73-84(?) 12 bolts will work, you just need to change the leaf/coil mounts. They are also 1.5” wider.
5speed: Best option out there but not the cheapest.
http://67-72chevytrucks.com/vboard/s...d.php?t=482069
Good luck!!