2016 C7 Z06 with a 2019 transmission HELP

[roxxc7z06]

Hi all, i have a 2016 z06 A8. Transmission was having some loss of acceleration, slipping etc. so we decided to install a brand new 2019 GM Z06 transmission part #19433321. filled with correct fluids, etc

Had the techs do the fast relearn and reset adapts-passed successfully, but when we test drove it
- 1st to 2nd - ok
2nd to 3rd - a little sloppy
3rd to 4th is aggressive, and once in 4th- the rpms just flare like I'm in neutral, it'll bang into gear like i got rear-ended.
It will then downshift back to 3rd. I cant even get to 5th,6th,7th,8th

Does having a 2016 z06 with that year T87 TCM(2016), need to be updated to a 2019 T87A TCM? Any help would be appreciated!

[relicdew]

Is this transmission part number backwards compatible? I thought I recently saw 2015-2018 Vette 8L90's have one part number and don't recall 2019 being on that list. I know we ran into unique issues with trying to run a 2018 Camaro 8L90 with a T87. It would have a harsh upshift to 2nd and not progress from there. Once we installed the proper engine/transmission computer the 2018 LT1/8L90 transmission started working properly. Not sure if you can successfully mix/match the controllers without an adverse affects.

[eastdawg737]

On the 2018 Camero, when you said ?proper engine/transmission computer? did you change T87 to T87a and upgrade to at 2018 ECU?

I?m in a similar situation with an 8L90 in a Sierra.