Going from memory 67 Dodge C Body 4 gear #'s are extremely low....55 or 56.I parted one ; a rotten Monaco 500 Fastop 383 4 gear Canuk car.It appeared to be completely virgin but when we tore the engine down it had 915 heads.Restored one -67 Monaco 500 convert for a customer ....it took over a year and lots of $$$ to find all the lower trim in NOS.This was a decade ago probably near impossible to do now.Still have a Canadian build 440/375 auto Ragtop in the yard but its pretty much gone.I'd like to see the fender tag info off your car.