A904 Neutral Safety and No Passing Gear

[cv70chall]

I just swapped out my A904 for a second A904 in my Challenger. My bad one was a 1970-71 model and the healthy one I installed was a 1967-68 model. Since the swap, the neutral safety switch works- BUT- the reverse light stays ON even in Drive, 2nd or LOW.
Did the earlier A904's use a different switch?

Lastly, when we adjusted the shift time (that the transmission goes from 2nd to 3rd) I noticed I lost my passing gear. What can I do to correct this?

Thanks!

[burdar]

I think both issues are the result of the earlier valve body.  You might be able to clean the old valve body and install it in the new trans.  I'll let the trans experts chime in just to be sure.

[cv70chall]

Forget the valve body- as the old 904 was scrapped. I was told there may have been a difference in the neutral safety switches from 67-68 and 68-upwards.

[burdar]

The arm on the valve body that the NSS comes into contact with changed over the years. You have to match the NSS with the valve body.

[cv70chall]

Sounds like it might be tough to do. I've heard there may be different switches for the earlier transmissions, too. I would naturally prefer not to do any surgery...