11' 5.3 boosted with 6l80 upshift issues....Hitting soft limiter?

Attachment 14706 Attachment 14705Yo EFI Live,

I've dug around and not found a solution that resolves my specific issue. I'm tuning an 11' 5.3 Silverado boosted making 450WHP.
I've adjusted up the torque mods in the ecm tune and adjusted shift times so the trans feels excellent except on wot upshifts. Here is the scenario, wot upshift around 5400 will feel like it is hitting a limiter, soft (like throttle pull) at first about 1 second, but if I keep the throttle pinned it will buck (like a hard limiter) and refuse to upshift.
If I back out to 3/4 throttle it will upshift.....My engine limiter is at 6k and I can bump the WOT shift rpm to over 6k and it still hits this at about 5400 RPM. I have not upped my d9420 table yet.
The only positive changes I have made are zeroing out the wot upshift speeds, but it still is not right. I reverted the upshift speeds back to stock and have not had any success ironing this out.
I've never had this issue and have tuned several 6l80's in vettes and camaro's over 700WHP......... I assume the weight difference is my hurdle and now I'm searching for some advise.

THanks for any input!

Nick

FIles attached are what I'm running now