Trans question/ Rock-on

[MDSheds_SS]

At WOT in every gear the car hits the rev limiter. 1/2. 3/4 throttle no prob, shifts are firm, and every gear shifts. Only when you plant it (wot) the trans acts like it's in neutral and bounces of the RL. Dropped the pan, filter is on, fluid is new, and I running a extra 1/2 qt This trans was built by Rock-on yrs ago. They are now out of business. Anyone have any ideas or here of Rock-on.
No SES light, 1 trans code P0748.
It also has Transgo hd-2 kit with vac mod and 3 washers.

[Mike]

Tune issue?

[MDSheds_SS]

Went threw the tune, and we don't see any issues there.

[xrelapse13]

unless it's actually slipping or hardware is messed up (which based off what you're saying it's not) the issue is most likely in the tune. have you recently changed tire size?

[MDSheds_SS]

Changed the fluid and filter again, running a full extra qt more now and when I took it for a ride it seemed to be OK. I will see what happens tonite at ETown. Hope it does what it's supposed to do.
Tires/wheels were changed but the ecm was adjusted for the size difference.

[xrelapse13]

everything work right at the track?

[MDSheds_SS]

Launched fine, for once. But it didn't upshift into 2nd and hit the rev limiter. Had to lift for it to shift. Taking the trans out on Monday and getting it rebuilt. I bought it used and don't really know truth about its history. I want to go 4000 on the converter anyway so while the trans is out I can get the new converter in.