1967 Camaro, 454 roller motor, 8.5" 10 bolt rear with 3.73 gears. I rebuilt the trans two years ago with PATC internals, h.d. clutches, upgraded intermediate sprag, oversize low/reverse roller clutch, new pump, etc. I was tuning the car and making great power so I decided to test it. Launched at around 3500 r.p.m. and everything was fine until I slowed down. No first gear! Second and third seem ok as does reverse. Any advice or suggestions? Thanks!

 

sounds like a check ball in the valve body is stuck.