727 transmission 3410668 vs 3410670

[DasFusca]

According to my broadcast sheet, my car came with a 3410670 trans. The docucments I have read, said that's for the 70 440 4bc, which came in the car when i bought it (numbers matching). My car has a 3410668 trans in it which documents show it's for a 70 383 4bc. I know that the trans was replaced.

The car was not running, so I have no Idea of the condition of the 3410668 trans. The Authentic Restoration guide and the Muscle Car Parts Interchange Manual do not mention the 3410668 at all? I think the 3410668 came in a Challenger.

My questions are....

1) are these two transmissions really just the same identically designed/built transmissions with different numbers?
I know the 6pack and hemi cars had special transmissions.

2) did the 1970 440 4bc cars have special trans too?

3)I was going to have a rebuild of this (3410668) transmission and put it back in the car. would it be better to buy a remanufactured 3410670?

4) is the 3410670 trans "special" in any way?

5)is putting the 3410668 transmission in my car a mistake?

 

[Greg Ducato]

The two transmissions may have different calibration to the valve body and governor and possibly the 383 may not have a 4 clutch direct drum, or 4 pinion planetaries but those can be easily changed during a rebuild by a competent shop.It would be nice to find the 670 trans but that may prove difficult to do.

 

[DasFusca]

The two transmissions may have different calibration to the valve body and governor and possibly the 383 may not have a 4 clutch direct drum, or 4 pinion planetaries but those can be easily changed during a rebuild by a competent shop.It would be nice to find the 670 trans but that may prove difficult to do.

Thanks. The only thing that makes me think that they could be the same is that the same 670 was used in both the 383 and 440 4bc according to everything ive read. I am curious of why have the 668 at all then. It had to be different in some way. Also odd that its not mentioned in either book but is on the list of identification from Chys Corp as being for a 1970 383 4bc.