After posting last message I crawled under my f600 with a eaton rear end two speed... and the slip joint section on it has less space then mine does now so I'm 95% sure now that when its loaded it pulls out of splines(showing more of the spline shaft). Or my f600 would bottom out when its loaded and it's all original. I know im comparing Ford to chevy which is probably a no-no to some ppl Haha. But the way driveshafts operate and adjust can't be different. If they are the same set-up that is. Now my f600 has two front shaft sections going to trans where my c50 only has one shaft going to trans from the rear ends shaft. But I would assume the back section that connects to rear end adjust the same way on both trucks.
