Shifting A Classic Mopar Into The ’90s
If you took part in our first Power Tour or read our coverage in the September ’95 issue, you may remember this ’70 Plymouth GTX. It was one of the HOT ROD Tour vehicles that couldn’t complete the 2900-mile trip. While the Ford and Chevy guys might get a kick out of that, it should be noted that the car’s demise was caused by a cracked aftermarket torque converter—the only non-Mopar part of its drivetrain.
While the obvious fix would be to simply replace the lame torque converter with a Mopar unit, 1500 miles of high-rpm Power Tour driving before the breakdown suggested there might be a better alternative. Why not install one of Chrysler’s new four-speed overdrive automatics in place of the original 727 Torqueflite? The reduced engine noise and improved fuel economy would make it even better for Power Tour ’96.
First introduced for the Dakota trucks in 1988, the A500 and A518 automatic overdrive transmissions are based on Chrysler’s 904 and 727 Torqueflites, respectively. Either transmission can be found in the Mopar Performance catalog, (part No. P5249165 for the A500 and P5249166 for the A518), and the gear ratios are identical to the older trannies, with the exception of the overdrive. However, the catalog listing included the ominous warning, “requires major modifications on A-B-C-E body.” After a quick call to Art Carr Transmissions in Fountain Valley, California, to confirm that he would help us perform the “major modifications,” we had Mopar Performance ship one out.