Whatever you do, don't force it in. Probably a good time to go back and look at everything again.
Make sure the nose of the transmission will fit in the pilot bushing, maybe the bushing got banged up and has a bur on it or is the wrong one. Make sure the clutch disc is lined up with the pilot bushing. Check to see that the release bearing will slide on the collar easily. Make sure the release fork is not binding on the pivot or on the release bearing. Hope this helps, Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine