burnt up powerglide

I just had this powerglide built this last month. I put it in the car because i broke the pump in the other one at windy hollow. This new trans is reid case and bell along with their roller tail housing, its got bte 1.80 straight cuts in it, 8 clutch forward drum, all the good stuff. The only thing used in the whole trans is a billet bte vavle body that i bought off one of these face book pages. its a billet non pro brake deal. Well, saturday Went to the track, went to warm the car up driving around the pits in low, it would go fine but about 100 yards it would slowly stop the car just like making a stop with the brakes, put it in hi, moved great. I checked the shifter adjustment and tried again, same thing, So i ended up not running the car at all on track, brought it home and pulled the pan. You could smell it was burnt up. The clutch pack in the rear is done, there is no friction material left on any clutches, this is just what i can see through the hole in bottom of the case, i havent disassembled it yet. Is there any reason or have yall had anything like this before? I guess its putting fluid into 2 different circuits at the same time?

Me, I would Skip Putting a FagBook Valve Body in a High Dollar Racing Transmission.

Your Last Sentence is Probably on the Mark.

I have that same valve body. It has been flawless for a few years now. Send it back to bte to get checked and fixed. Also reverse clutches need plenty of clearance. If I remember correct about .080 to .100 .