The good stuff from B&M. To...
The good stuff from B&M. To upgrade our automatic-equipped Charger, we tapped B&M for their Transpak calibration kit, a flexplate balance-matched to our 440, a new Holeshot 2400 high stall 11-inch converter, and the SuperCooler to let it live.
Introduced in 1962, the 727 TorqueFlite is considered by many as the best performance three-speed automatic ever built. The 727 was available over the years behind any of the modern Chrysler engines, from Slant Six, through the small blocks and big-block V8s. Back in the early '60s, when it first hit the strip, the combination of the TorqueFlite and Max Wedge was indomitable, giving Chrysler a hammerlock in the top automatic classes of the eliminator. Right from the outset, the stage was set for the 727 to become one of the most respected transmissions in racing, a position the unit would enjoy for decades. That's not to say that the mighty TorqueFlite is perfect. In the case of the average street unit, the specifications can vary greatly, depending upon the original application.
Not all TorqueFlites are created equal, nor should they have been. What was ideally suited to the dragstrip certainly wouldn't fit the needs of the Imperial customer, and no sane manufacturer would put the same trans behind the Slant Six as a Six Pack 440. Major internal differences included the number of front clutch plates, governor weights, and line pressure specifications which varied up-shift speed, friction material and band construction, the number and tension of the clutch springs, and factory torque converter stall speed-just to name a few. Basically, the performance and torque handling capacity of the units in O.E. form was directly related to the performance and torque capacity of the engine. The highest capacity units were the relatively rare five-disc front clutch Hemi TorqueFlites, used behind the Hemi and 440 Six Packs. While the specs varied widely, the performance of any TorqueFlite can be greatly enhanced with aftermarket components for outstanding street performance.
While a lift would be nice,...
While a lift would be nice, we performed the modifications in our driveway, with basic hand tools. It helps to jack the car as high as possible for clearance, which requires H/D jackstands, securely positioned under the chassis.
In our case, the TorqueFlite behind the 440 Magnum of our '71 Charger R/T was the common four-disc front clutch H/D unit. While the shifts were crisp, there was room for improvement. Bang the Slap Stick back to First, mash the throttle, wind the engine up to 5,500 rpm, ratchet the shifter forward, and the trans would not respond-5,600 rpm ...5,700...5,800...5,900...6,000+ and then it would finally shift. While it is normal for the automatic to hold briefly when making manual shifts, in this case, something was definitely amiss. Leave it in automatic mode, and the shifts would come in at a meager 4,400 rpm. Definitely control problems here. While our particular unit would give tire screeching shifts, the terrible shift control made our good-shifting trans worthless for performance use. The problem was in the valvebody, and our plan was to go in and reprogram the trans with a B&M Transpak.
Valve Body Modifications
While the Hi-Po factory transmissions would deliver fairly snappy shift performance, if the 727 in your application was lifted from under a New Yorker, truck, or any standard factory application, the emphasis when the trans was assembled would have been on seamlessly smooth shifting rather than speed. Flick the shifter in one of these units, and shifts can only be described as Whaaaa...Uuuummmph-slow. The B&M Transpak contains the pieces and instructions which allow the trans to be recalibrated to three different levels of performance: H/D Towing; Street Performance; and Competition. In our install, we went somewhere between the Street Performance and Competition settings.
 Access to the torque converter...  Access to the torque converter is gained through the cover plate. On big blocks, a few small bolts, and you're in. |  Since the torque converter...  Since the torque converter was being replaced, the trans has to come out. Dropping the driveshaft is a good place to start. Four bolts at the rear straps and it'll slip out of the splines at the back of the trans. Have an extra yoke handy to shove back in the trans, to avoid taking a bath in ATF as you pull the automatic. |  The starter will need to come...  The starter will need to come out. Make sure the battery is disconnected before beginning the job. |