What parts can be used on '68 C-20?

[special-K]

Ok,you have a Dana60 coil rear.A simple no wrench/oil way to do ratio check is make a tire`s location on the ground and mark the driveshaft at the rear housing for reference.Jack up that tire and spin.Count how many times the tire spins to the one turn of the driveshaft.Just a bit over 3 revs would be the 3.08 or Dana equivalent.At 3 plus about 3/4,it`s a 3.73,at 4 plus a bit,it`s a 4.10.
There were two axles used in these trucks,Dana60 and Eaton HO52.The two companies varied their ratios a bit,but real close.The big blocks with Turbohydramatic trans came with the higher 3.08 ratio standard.
If you do swap to 1/2t suspension,you can bolt a coil 12-bolt rear right in there.The`78 could be used,too.