To answer your questions regarding the BW35--they are all basically the same but for some minor differences. The 122's and early 140's had a longer tailshaft section and are air cooled (there's no trans cooler built into the radiator--instead the torque converter has cooling fins) -- that's the major change. At some point the position of the neutral safety/reverse light switch was changed - minor. One problem area of the 35 is the reverse band servo - easily accessed after removing the pan - problem # one - the "O" ring around the servo piston can wear out/tear leaving you with no reverse--problem # 2 - the two 3/8ths inch dia. bolts securing the actuating lever loosen, again, leaving you with slow/or no reverse engagement. The 35 is a sturdy enough unit behind a 4 cylinder (164's with the 35 experience far more trans problems despite their beefed up clutches) and was used by many British cars (BMC/BLMC, Rootes and Rover to name a few). Be sure to use the proper "F" type fluid.