1991 Chevy camaro ls1 hard high rpm shift 1-2 have to let off gas pedal for it to shift changed shift solenoid changed tps no vacuum leaks any suggestions

 

It has been a while since I worked on a trans, but it sounds like the pressure is either not high enough or too high, which is causing it to not shift correctly. Just the first thought off the top of my head from memory. Are there any other shifts that are hard or not happening at the right times or you have to let off of the gas for?? Have you checked your trans fluid level and condition?

 

Fluid level and condition are fine no burnt fluid could it b that the pressure solenoid is not providing enough pressure to reach accurate speed and rpm to shift?