Vote for The Forward Look Network on the Mopar Top 100 Sites 

New subject: tranny/engine compatibility

From: Bob O.
Date: April 03, 2002
Time: 19:38:16


This engine/tranny compatibility is very confusing to my simple mind. Can anyone straighten this out? (the problem, not my mind.... that's beyond help). I'm just going to blabber on with what I think I've found out, and more knowledgeable people will no doubt correct me. So let me see how much of this I've got around my neck: the early Torqueflite transmission (the A466 model?) was cast iron, and built from 1956-1961. It was 3 speed, but lacked "Park", although some had a drum-type brake on the tailshaft, and a lever near the pushbuttons which operated this. The aluminum Torqueflites (A727) were introduced in 1962, and used pushbuttons from introduction to 1964, (although some had floor or column shift?) and then from 1965 no more pushbutton trannies were made. At some point (1962?) a "Park" selector was added, although initially this was connected to a second cable and operated a sprag in the tailshaft area (?), whereas from 1965 the column or floor shifter operated linkage (no more cable?) and a real "Park" was internalized to the valve body of the tranny. In swapping trannies and engines, a person should be aware that the cast-iron trannies had a smaller splined input shaft (same size as the Powerflites?), so need to be mated to the correct early torque converter, and that these early torque converters had a "boss" sticking out of them them which fitted into a recess in the crankshaft flange. If you try to mate a 1962 or later engine with an earlier converter and tranny, you need a spacer plate to compensate for this, (which means your engine mounts will probably have to be moved forward as a result?). This is not a problem if you put a pre-62 crank on your engine. There's something else complicating swaps that I don't understand.... a "slip-joint" connector on the engine output shaft on later engines as opposed to the bolt-on flange? What in barking ale is that? In my 1960 Plymouth manual they describe a Torqueflite 6 and a Torqueflite 8.... the 8 definitely looks bigger and meatier. No mention of any difference then between the small block poly 318 and the big block 361. Later on at some point does the Torqueflite 6 disappear and instead there are big block Torqueflites and small block Torqueflites? (if so what did the sixes use?). At some point (after 1965?) the bell housing bolt pattern becomes different between the small and big block combinations. Finally, if you want to put an aluminum tranny and keep pushbuttons, it is easiest to do so if you chose a pre-1965 Torqueflite, although apparently you can engineer a later 727 to be pushbutton operated, if you're ingenious and enjoy the kind of frustrating activity that makes me scream and start using a 2 lb hammer. OK, so I know this is probably mostly if not completely wrong. Any help in clearing it up would be gratefully accepted.


Last changed: May 04, 2010