Hmmm... Earlier you mention "I need to focus on a pre-1986 AOD trans ".
I'm with BlueOval - that may not be the best path. Prior to '88 AOD's did not have the lube style Output shaft & were prone to failure. There are also 3 different Overdrive Servos available with AOD's - You don't want the "C" size servo as it was prone to slip off under stress. They were on most AOD's prior to '85.
"The "A" servo is the largest overdrive servo available for the AOD transmission. This piece is used only with 1992 and 1993 trucks and the Thunderbird "Super Coupe" supercharged 3.8 Liter V-6. It will provide a 50% increase in band application force over the small "C" servo and 16% over the "B" servo."
At a minimum I'd look for an AOD with at least the "B'' size servo - post '85 V8 Applications, all 351's, & the high output Mustangs & Lincolns. If you are going the salvage yard route look at '92 & '93 trucks or the larger engine Tbirds.
I hope that helps. We went with a Kevlar "B" sized servo in our AOD behind our upgraded 351W. We also added a Baumann Engineering shift kit to smooth out the shift points. If I had extra cash I'd also go with a solid upgraded valve body (Baumann, Silver Fox, etc.) - that dang cable is very sensitive & adjusting it to get the shift points right while keeping the pressure within spec is a painful experience.
Good luck over there. (I'm not a transmission expert just had to learn a lot about AOD's as part of our truck build).
Ben in Austin
1950 F1 (351W/AOD)