Asking about differences if any in transmissions...John Kunkel???

[TylerCharger69]

Is the transmission from my 383 '69 Charger any different than a '78 440 transmission from a police car?  Other than the obvious external differences.  I know it will bolt in with no problems, but I noticed the flexplate on the 78 tranny is smaller in diameter meaning overall size and bolt pattern, so Im assuming the torque converters are different.   What about ratios?  Both are 727 torqueflites.   Any other specifics will be much appreciated!!

[RD]

yes they are different and no i am not john kunkel.

differences are in the valve body, intermediate band, input shaft/drum bushing sizes, belville springs, front servo piston assembly, front pump ventilation design, and rear tailshaft housing.

other than that, they will bolt up the same.

the differences in flexplates is the larger flexplate fitting a 11" converter and the smaller flexplate fitting a 10 3/4" converter.

ratio differences, none in the gears, but the intermediate band shift lever may have a different ratio based upon the application of the 69 transmission.

78 big block transmission, SOME BUT NOT ALL, had lock up converters.  you can tell if yours is a lock up by looking at the end of the input shaft.  if there is a machined area that is about 1/2" in length at the end of the input shaft that is smooth, of smaller diameter than the rest of the input shaft, and NOT splined, then you have a lock up.  if the input shaft IS splined to the very end, then it is a non-lock up.

tailshaft housing on the 78 will have two threaded holes at the very end for a counterbalance whereas your 69 will not.

lastly, how specific are you wanting to know in regards to the two?  is this a simple, will it work or not? or is it a question that will require a more indepth study of the valve body passages, performance possibilities, and overall ease of the checkbook?

[Challenger340]

Where's Kunkel when ya need him ? LOL !

I think, one of the Valve Body differences is the "part throttle" kickdown for the later Transmissions, which the '69 does not ?
and,
Neutral Lubrication circuit as well in the later trans ?

John ?

John ?

are you there ?

[John_Kunkel]

Prior to '78 a 727 could have either a 10 3/4" converter or a 11 3/4" converter, starting in '78 they eliminated the 11 3/4" and went to strictly 10 3/4" so the flexplate would need to be changed to use the '78 trans. Also, the '78 440 would most likely have a cast crank so the converter would be externally balanced. Knock the weights off of the '78 or use the '69 converter.

There was only one big block 727 ever made with a lockup converter, it was used behind the 400 in some '78 wagons so, if this unit definitely came from a 440, it isn't lockup. The stamped part number for the lockup trans is 4028824, few survive because they didn't work too well and were often replaced with non-lockup units when they failed.

Neutral pumping was never a problem but pumping in Park was and the factory never did anything about it. Yes, a '78 would have PTK.

Gear ratios for the 727 were the same from '62 until the end of production.

[TylerCharger69]

No worries there....The 440 im building is the engine that was mated to this transmission....so as far as the external balancing....No troubles.   And...i have the flexplate that goes with it of course....i was speaking i guess in terms of performance

[John_Kunkel]

From a performance standpoint the 10 3/4" converter is better than its larger counterpart, the factory stall spec for a 440 HP was 2500-2800.

[TylerCharger69]

Thank You, John.....I figured if any one here knows transmissions.....You're the man to speak to!!