Getting that ever-so-desirable overdrive gear in a classic Mopar has been a quest that has stumbled many an enthusiast. Certainly aftermarket options abound like a grenade-proof Gear Vendors Under/Overdrive; a smart Tremec 5-speed swap from American Powertrain; or a modernized “A41” 4-speed 4L60E adaptation. But if you’re looking for a solution for your ’67-’75 A-Body that’s a little closer to factory, then Auto Metal Direct might have you covered.
Between 1989 and 1990, Chrysler offered the A518 overdrive automatic in its truck line. Essentially a 3-speed TorqueFlite with a 0.69:1 overdrive incorporated into the tailcone, the transmission strictly came using the A/LA bell housing bolt pattern, meaning no B/RB (383, 400, 426W, 426 Hemi or 440) applications. (And no, the 47RH – essentially a beefier A518 with added clutch capacity that was behind both the 5.9 Cummins diesel and 8.0L V10 – has a different bolt pattern).
Per AMD’s site, the US Car Tool-built crossmember is “made from 3/16″ thick steel […] additional clearance may be required including cutting the factory crossmember for the transmission tail-shaft and the speedometer or VSS cable/sensor. The factory floor remains in the original location. Requires welding in the replacement USCT transmission mount tab. The tab is designed to accept the common GM stud-type transmission mount (#10473052).”
The USCT 518 overdrive A-body crossmember is fully boxed to provide the structural integrity that would be lost by removing the factory crossmember. The kit includes the crossmember, lower transmission mount tab, Grade 8 mounting hardware and instructions for installation. The GM style insulator (#10473052) is not included and is available in almost every auto parts store.
