I have a hughes street/strip th400. 600 easy miles on the transmission behind a carbureted stock vortec long block. The other day the reverse appears to not be working. You can feel it shift into reverse but the car doesn't move (it doesn't feel like neutral, I have a little binding type feel but still no tire movement). I pushed the car out and did a road test. In drive I have good shifts from 1st to 2nd to 3rd. I also went the manual shifting route and all forward gears work fine. Fluid level is good and linkage doesn't appear to be the issue. Any ideas???