I have a 66 Barracuda with a A904. It will not start in park but will in neutral. I have tried 2 used and 2 new NSS's and still have the problem. The trans is a new rebuild. I dropped the pan and shifted it thru all the gears and noticed when in park the rooster was not and could not reach the pin in the NSS to activate it in park. The rooster hits the stop components before it can activate the NSS. So is there a way to adjust the rooster comb inside the trans?

 

Found the problem. The arm on the manual shift lever ( rooster comb ) that goes to the manual valve was bent so not letting shifter go all the way into park. Replaced with the comb from my parts car, now all works good.

 

Awesome !!!!! Thanks for the update... I would have never guessed that was the issue.... Mopar on !!! Cheers