For our '71 Satellite, the swap looked like a winner, since we were favoring retaining an automatic transmission. The transmission is available in torque ratings of 450, 550, or 650 lb-ft, so we were confident in the power handling capabilities. Keisler custom tailors each kit to each customer's needs, and for our 340-powered Satellite, we specified a 550 lb-ft unit with a 2,800-rpm stall converter. The converter stall speed can be had at a wide range of ratings, depending on the specific requirements of the installation, and the beauty is that once the trans goes into lockup, all of the lost rpm and slip normally associated with a loose converter are gone.

We took our car to D&P Classics, an authorized Keisler dealer, to install the A-41 conversion. Basically, the job consists of two parts, the mechanical aspects of getting the old trans out and bolting in the A-41, and the electronics portion required for the transmission control. The Keisler kit comes with a harness that is fully terminated, so it is just a matter of plugging the harness ends into their associated connectors. A control unit is part of the package, and though it is fully programmable for altering the transmission functions, it is already set up by Keisler with a base calibration that is ready to go. Any changes to the calibration are simply made with Keisler's included software package via a laptop computer.

We quickly had the original 904 Torqueflite on the ground, and then pre-routed the harness into position as indicated in the thorough Keisler instruction manual. The control unit was mounted behind the driver's kick panel, and we moved on to hoisting the new trans into position. Any time a non-original retrofit is attempted, there is a question about just how well the parts will fit. Keisler makes a note of some minor clearancing of the firewall pinch weld, and no other "massaging." We swung the A-41 up to the waiting block, bolted it up, bolted up Keisler's custom crossmember mount, and it was in just like that! From there, the actual nuts and bolts of the install was no more complicated than a normal transmission replacement: hooking up the cooler lines, the shifter, torque converter bolts, and starter. Each kit comes with a custom driveshaft, and we ordered the upgraded aluminum 'shaft.

We wrapped up the full swap at D&P, spun the Satellite around the block to check the function of the A-41, and then it was trial by fire in the form of a 200-mile trip back home. With a trip of similar duration down to the shop still fresh in our mind, the contrast was staggering. The Satellite was at its worst in open highway driving, winding tight in the slow lane while traffic whizzed past. The noise vibration and harshness that were all part of the driving experience were gone. We slipped into the left lane with the hammer down, making time at a leisurely 2,400 rpm, a difference as clear as night and day. With the lower first gear ratio of 3.06, the launch off the line was the equivalent of a set of 4.30 gears with the old Torqueflite. Up into overdrive, and the final drive equivalent is an easy-cruising 2.51. That is the advantage an extra gear can make to the ratio spreads.

Keisler's control unit actually accepts two calibration programs, selectable from a dash-mounted toggle. We had a "cruise" calibration for normal driving, and a "performance" setting a switch click away. The A-41 and our converter combination, with the gear ratios involved simply made the car an animal in "performance" mode. Gear multiplication, perfect stall, and solid, quick shifts make that happen. The final upshot is the trans will just shift into overdrive, then lock the converter, and you're moving down the road like you never figured an old Mopar could.