I can't even get enough clearance to get the top snap ring back in. The piston is installed properly and bottomed out and the bottom snap ring is in. Any ideas?
I think your using the clutches with the crosscuts on them, they are for the direct drum, they are thicker than the smooth ones which are used for the forward drum/with input shaft. It's nice that your learning new things as you walk through the process.
I'd take enough clutches/steels out to get the snap ring in and measure the clearance. Then measure the clutches/steels you took out. That'll give you an idea of how much you need to shorten the stack.
I'm with the others though. You probably just have the wrong clutches in there.
Update: sooooo turns out I was using the bottomed snap ring on the top... lol and yeah it was pretty dry due to me taking it apart multiple times, I drenched it and resoaked the clutches tho.