There are several leaks that can be easily addressed in a TF without dropping the trans: Oil pan, rear seal ( where the driveline goes ), shift shaft, kickdown lever,disptick tube, the little gasket where the plate is that covers the snap ring on the output shaft - seldom noticed as often the crossmember is in the way , and the little gasket where the neutral safety switch mounts. If I had a leak at ANY of these, I would be more inclined to fix them than to just add Trans X. I have used the stuff, its basically Rislone or Alemite CD-2 for your trans as opposed to your engine. As far as the common malady of torque converter drainback , where the converter drains back into the trans and overfills it, its a transient thing and if the trans is sealed well it shouldnt cause huge amounts of leakage. Once you restart the car, the fluid is pumped back into the converter where it will stay unless you have a prolonged shut off period. Besides the parts that Pat Blais sells ( btw, if youre in the Northwest hes probably the best TF guy for parts and service - and no I dont work for him ) there are some parts from Trans-Go that address the drainback issue as well. As far as the person who asked about parts or repair interchangeability and commonality, the main changes that occurred in the TF were going from cable and pushbutton shift to the mechanical rod linkage in the column or floor shift cars, the change in the speedometer gear and cable around 63 (?) , the removal of the rear pump I think was in 65 , the torque converter spline change and input shaft change was after that and there were more minor internal changes as the trans evolved. Most of these changes wont affect any of the basic do it yourselfer kind of things such as gasket or seal changes or basic trans servicing. Mikey 62 Crown Coupe