4t60e I get AB code. NAPA says there are 5 selenoids,what order are they in?

Yes they are they are the same I think after 97 when they changed to 3800/2 from then on they stayed with same 97 is a 4t60e call trans shop to confirm it's not like mine

No the 95 is a 4T60E transmission. It's electronically controlled via the ecm on your vehicle. The 91 is a TH440T4.and is not electronically controlled. Transmissions are wired different and will not work correctly due to the ecm controller. Ther are plenty of 4t60e trannys. in the salvage yard as they are used in many larger gm vehicles.

shifter cable has went bad replace shifter cable.

http://www.makcotransmissionparts.com/4T60E.html
click on the link once on that page you will see:
Click here for
4T60, 4T60E
Transmission breakdown illustration

That is not a compatible transmission for that vehicle. The 91 transmission is either a 4T60 or a 4T60E transmission, and the 98 Century should have a 4T65E transmission.

Shift solenoid ,manual shift valve, blockage in 3rd gear circuitry, defective band and clutches.

filter and fluid and check seals front and rear if dried or nicked replace

NO just the side cover. The frame cradle will have to dropped.

Depends on what engine is in each of the vehicles. Assuming that the 1992 Park Avenue and 1995 Buick Century both had similiar engines (both being a V6), then they would both be equiped with the 4T60E transmission and you should have no problems interchanging them. Any differences (if any) in the wiring or valvebodies can easily be changed from one to the other and will be fairly self-explanatory.

Hope this helps and good luck!

should be on the side of the transmission with a vacuum hose connected to it