New build turbo 400 with Hispster t-brake RMVB behind approx. 800hp BBC. Tight 9.5" nitrous converter (approx 3800). Car has been street driven about 20 miles so far. Problem is when the trans gets some heat in it it has a hard time moving in reverse. RPM's have to come up quite a bit to make it move. I am using neutral and t-brake for reverse. Moving forward all three gears shift great with no lag. Also t-brake holds in first gear with no sliping or car movement. Any ideas where to look first? Thanks in advance.