TR code on the door tag is 5 characters long, not two. The first character in the transmission code. The last four are the coil springs codes.
For 1993 there were only three possible transmission codes...
2 = manual Borg Warner 5-speed T-5 (2.3L or 5.0)
L = automatic 4-speed light-duty (A4LD, 2.3L only)
T = 4-speed automatic overdrive (AOD, 5.0L only)
Same transmission code is in the middle of the first line on the (1988-93) buck tag, after the VIN engine code...
A2 = 2.3L (1988-90), T-5
AL = 2.3L (1988-90), A4LD
D2 = Cobra 5.0L, T-5
E2 = 5.0L, T-5
ET = 5.0L, AOD
M2 = 2.3L (1991-93), T-5
ML = 2.3L (1991-93), A4LD
1979-87 buck tags did not have a code for the automatic transmission. The spot was left blank. The only exception I'm aware of is the auto behind the turbo engine in 1980 (code TCA).