mating transmission to engine

[reluctantartist]

I completed engine rebuild on a 1982 vanagon, and i am at the installation point. I can't get the transmission to go the final 1/4". I ended up dropping the transmission and trying to mate it with the engine out of the van. I've rechecked the clutch disk alignment I even mated the tranny without the clutch to make sure nothing was bent, But, one the clutch is on I can't get it to go all the way on. I get the splines lined up and it slide in but not all the way. Does anyone have any advice on what to do or what to inspect. I have removed and installed transmissions before without any issues.