I Just bought a 67 Dart 340 4 speed.. It was stated to have a "posi" 8-3/4 rear... I tried to do a burn out to check the dual traction rear with no noticable 2 tire burn marks, due in part to the type tires and the cold weather... Next step I put the car up on 4 jack stands to check the car out completely for castings, leaks, etc... Well, when I got to the rear, with it in gear, and turning one wheel ccw the other wheel went the other way, cw... Then I put it in neutral and did the same and the other wheel didn't move, but the drive shaft turned... To me this means an "open" non-posi rear... Am I right?.. I inspected the rear and the drums look small... The pumpkin casting numbers were 1820657 which in my books is a 8-3/4 C body rear from 58-64... Is this compatable with later posi's?.. Can I swap out this pumpkin with a later posi?.. Will the axles be a match, etc... How about gear ratio switches?.. The 4 speed is from mid year 76 which I've been told is Over Drive 4 speed tranny... Thanks for any help...
