I have no dog in the fight, but people did unusual things back then, sometimes for a purpose. I believe that I remember seeing at the Gibb reunion, a 67 L78 Camaro royal plum convert, that was ordered with a 308 gear. I believe the owner ordered it that way because he wanted to run down the interstate at 100+ mph. Not everyone back then wanted to go quick fast. Some wanted to go top end stupid fast. As in out run the cops for whatever reason. I remember a particular 64 dodge that could do that pretty well.
FWIW
Carry on.
