Transmission Won't Slide All The Way In

Need some tips here. I pulled my T5 and replaced it with a new built up unit. I was having this problem where I can't get it to slide on that last 1/2". So I pulled the whole thing off again, also the clutch and pressure plate and test fit the unit. The bell housing bolted up nice and flush with the block and the input shaft fit the pilot bearing perfectly. I put the clutch and pressure plate back on, and I can't for the life of me get this last 1/2" gap to close again.

I have put the tranny in 3rd gear and used the drive shaft to rotate it to get the splines to match. I confirmed by hand cranking the engine and I could see the shaft rotate.

Any tips? I've been wrestling with this thing for 3 days now.

EDIT: Just thought of something- if anything, it seems its getting caught on the bearing retainer. This transmission was built specifically for 94-95, however, I am wondering if they mistakenly put the wrong bearing retainer on? It is an aluminum shaft like all other 94-95 retainers with a steel base. Is the 94-95 retainer typically shorter or longer than the 86-93s?

Thanks for the tip! I did not hook up the clutch cable yet, that sounds like a good idea. I will have to bribe one of my totally unreliable friends to come press the clutch for me.