904 Lost Acting Up

Sooo a few months back I had a well known and respected Mopar mechanic buddy install a brand new Turbo Action forward pattern manual valve body in my 904.

Once it was installed it shifted VERY hard, shook the car pretty good . I also noticed I had to give it quite a bit of gas to move in reverse. I didnt feel like something was binding but felt more like reverse just wasnt engaged all the way. Smooth but needed a lot of gas.

I asked him about it and he said check the fluid level, which was good. But thats where it left off because I was racing it the next weekend. Went racing and everything was working as I described above, shifting hard and reverse sucked. Got home that weekend and parked it for several weeks at my parents because I was moving. So I go to my parents the other night to pick it up and everything is still the same, until I get 1/4 mile down the road. I should add I wasnt beating on it for that 1/4 mile, no more than 3/4 throttle. Then all of a sudden the tranny acts like it was put in to neutral. First, second and third all felt like neutral.

Any ideas? Plan on taking it to a tranny shop that works on mopars for a diagnosis. If its blown Im not sure if I want to have it rebuilt or build a 727. I plan on a 408 build in a few years so Im not sure the 904 would hold up to that kind of power anyway. Any thoughts are appreciated.