Never had this issue before so I'm a little lost. The Dana 20 Has Been Coming Out of gear while cruising on the hwy or around town. Any ideas. Phil rebuilt it so it is in good shape

Weak spring.

Interesting, pretty sure he's rebuilding them with dual springs, I'm sure he'll post up a recommendation.

It does have dual springs and J type ball pockets. Make sure the rear shifter isn't rubbing anything like the floor sheet metal. Also look for a bent or severely out of balance driveshaft, loose rear yoke, or loose trans to tcase bolts. I know everything inside the case is in good shape.

Just a thought, we swapped the side that the linkage was on for the twin sticks, do you think it may be hanging up on something or maybe the "throw" isn't long enough.

I do have a little vibration in the resr. I replaced the rear slip yoke and never had it rebalanced. You think I need to check all the bolts on the tcase , tranny, X member? How tight should the bushing bolt be? Where do I just re balance a drive shaft?