Well after 4 years of beating the heck out of my '79, the rear main seal just started leaking (it's wetting my h-pipe a little and dripping at idle). I've got my car on jack stands and bricks and have the driveshaft, h-pipe, and starter out (along with other little things that are in the way) and will finish changing after Thanksgiving (cause I'm leaving tomorrow and don't have time to finish it b4 I leave--- I'm pulling the tranny). Seal cost me $17 at local Ford dealer. So total cost = $17.
I dunno, but to pull the tranny (especially when a shop is gonna have a lift) and replace the rear main seal should be AT THE MOST $200!