95 Drive Train Troubles

[elanman]

We have a 95 350 and what has happend is got shifted from Rev to first at a slow speed yes ouch, The front still works fine but the rear makes a sound like something got striped or a gear wear the driveshaft goes in the back of the motor ? How can we check this to see what damage was done and wear ? and place to get parts would be great as well ? Thanks for any and all help in advance.