i think you are talking about the B&M hammer (rachet) shifter, not a shift kit. a shift kit goes inthe tranny itself.
i have the B&M shifter too and love it! never had a problem with it. it sounds like when u put the shifter together u forgot to put the retaining clip in that holds the shift lever in.
i believe hurst makes a shifter for the auto, and i have seen people put the B&M "pro stick" in mustangs too!
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89 GT AOD w/ shift kit, B&M rachet shifter, Trickflow intake, Crane (E-type) cam, 70Tb, 75MAF, 1.6 Rockers, Pulleys, MAC headers and H-pipe, Dynomax mufflers, K&N, 3 core radiator, white face gauges, custom interior, cobra R rims. 14.9 at 95.07mph with stock 2.73's.
89LX 2.3 Notch, daily beater!
MY89GT