Can you move it forward? If so, it wouldn't be a clutch problem. And also not necessarily a transmission problem.
I would look at brakes. Possibly one of the shoes has stuck to the drum and won't let it turn.


Kevin
1951 Chevy 3100 work truck
Follow this saga in Project Journal
Photos
1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car)
Busting rust since the mid-60's
If you're smart enough to take it apart, you darn well better be smart enough to put it back together.