i got home earlier than anticipated today so i was able to get a little more done.
I shoved both axles in the housing with the diff in, there is a good mount of spline angagement. With the brakes off and the trans in neutral i spun the driveshaft and both axles spin. if i spin one axle the other one moves too. it works as it is supposed to by hand.
The axles are not equal length. Driver side axle is 19 7/8 pass side is 17 5/8". or close to that.
The chassis guy is a mopar guy, he ran mopars for years and years.
I pulled the diff out and have it on my work table. I will hopefully pull it apart tomorrow after work.