Long while back, I got a transgo shift kit for an A999 torqueflite. I remember that I looked up a whole bunch of stuff, when it came to installing it. I never actually did install it though. Plan's changed and I sold the engine I was going to attach to it.
Anyway's, not sure if I'm remembering correctly, but I don't think you had to disconnect shift linkage or kickdown. When you get to it, you can just unbolt it, and it comes out. For my shift kit, there would be a little work i'd have to do to the valve body.
Now, this is just going off of my memory, which isn't the best... but that's what I could come up with. For more info, keep looking it up. Better yet, look up a tear down video on youtube. there should be one.
1990 Grand Wagoneer-"The Crapwagon"
AMC 360, TF727, NP229, 3.31gears, 2" lift
Rancho 44044, Rusty's 2" AAL, TFI
...not too rusty anymore
Plenty of patina
1926 Dodge Brothers Business Sedan 212 I4-CRANK START
1987 Lincoln Town Car Signature Series-5.0 AOD (WD)
1987 Dodge Dakota LE 3.9, A999, 3.90 gear (DD)
1994 GMC 'Burban 5.7, 4L60E, NP241, 3.42 gear (DD)
2001 Jeep Cherokee 4.0, AW4, NP231, 3.73 (limbo)