I did a 4L80E swap among other things and stuck my driveshaft into the NP T-case I'm using and this is where I'm at. It goes pretty damn far in there so I'm afraid of it damaging the case. How much clearance do you generally see when looking at the driveshaft mounted to the back of the case? I marked where it stoped going in (give or take 1/8 of an inch). Could I actually be alright with the way it is?

 

You could take it to a shop and let them take off an inch just to be safe.