Tony, I take it you have the corperate rear in your '68. If your really into swapping, I used to drive a '68 C-20 stake truck. It was a factory stake with coils and the factory overloads. It had the Dana 60 rear with 4:11 gears. I may still be able to get my hands on the truck, which went to a local scrap yard after the guy i sold it to parted it out.
Since were talkting about our rear ends, does yours (truck) have excessive play in it, i.e I can turn my driveshaft about a eighth of a turn before the play is taken up. I can also feel the slop in it when driving at slower speeds. I have a spare with 4:11 gears, and it feels a lot tighter. Not sure if this has anything to do with the taller gears, or wear.
The 1973 and up 14 bolt is a fairly easy swap, requires the spring pads to be re-located. I have been told they use the same U-joint.
