My 76 GMC body sits on a 1981 Chassis. I get confused too.
Would a new or modified driveshaft help the problem?
In Pine Bluff, the place for driveshafts is the local machine shop. They prefer you to take the vehicle there on a trailer and the Machinists do the measuring.
If you measure it wrong, they charge twice, If they measure it wrong it's on them.
