The clutch fork and TO bearing need to be fully assembled before stabbing the trans. Most bell housings don't allow enough wiggle room to insert the fork once the trans is in place. Get a couple of trans to bell housing bolts installed loosely, then push the clutch pedal down and shove the trans into place. On a big heavy trans I've also used a come-along or big bungee cords to make the trans and bell housing mate up.
Jerry
I wish I had read something like that a couple of years ago, When reinstalling my SM420 into my 3100 I thought it would be easier to install the fork after the trans was in place since it is a bit of a struggle doing this by myself. Got the trans fully in place then spent a couple of frustrating hours trying every which way to get the fork in place. I even unscrewed the ball mount thinking I could thread it back into place once the fork was close. No joy. Had to pull the trans and start over.
