I say keep it stock related. Keep the straight axle, drop it and add lowered springs if needed. install a 250 or 292 engine, but front mount it so you can go back to a 215 or 235. Do custom padding on the seats, i did on my 55, different foam cut in triangle shapes to support the front and allow ssofter foam for your bottom. Upgrade the rearend to a 3.55, it will cruise 65-70 easy, more if needed with a 6 cyl.
Just remember to move a little while turning and it will drive fine.
Devin
