Loses power to the wheels after short time

[HerAlpha]

First post need help and can't find a forum with similar issues. 2010 camaro ss, procharged, cam, exhaust, heads, stage 3 trans circle d 3200 stall 750rwhp. Brother in law needed help with the car. He sadly got royal screwed. Factory trans blew for obvious reasons. A localy known performance guy was supposed to swap it to a 6l90 from ctsv. After 6 months at the guys shop we had enough and brought a flat bed to go get it from and it was in pieces. After putting the car back together, custom driveshaft etc and firing it up turns out trans was swapped with a 2014 6l80 from 1500 and was shot as well. Took it out had it rebuilt stage 3 from an actual performance shop. Reinstall went seamless, tcm flash to prior trans as well went seamless. Doing break in period (driving like Mrs daisy) after about 60 miles lost all power to the wheels. 3min after sitting back to normal for a mile or 2. Brought it home and all the lvls are good no burnt smells or anything but still can't loses power to the wheels after 30-45sec. What do I need to check/change in the tune (trans has very mild/stock tune)? I've been using HTP for 7 days so I'm an absolute pro. (Sarcasm helps with my self confidence on bad days)

[Tfoggy]

My guess is a bad TCM in the trans itself...
Def will NEED to have all good stage 3 PLUS hard parts and clutches to hold a S/C LS3

You can try a Relearn procedure and see if that helps.. But I'd put money on it that it's a trans/trans tcm issue.. NOT a tuning issue