trans expert needed

I m going to put a 99 trans in a 95.
Hollender says it wont work.
GM reman has different part# for these
95-6
97-8
99
I think Ive got it nailed as to what parts I need to keep off the 95
to make the 99 work but need to be sure.
If anyone is or knows of a good trans guy LMK thanks

obd1 vs obd11, are the electronics compatible?

Yes its the same trans for 95-6
95 OBD1
96 OBD2