[big gear head]

That is the 8.2 10 bolt. The ratios that are available for that rear end are 2.73, 3.08, 3.36, 3.55, 3.73, 4.10 and 4.56. Which one is right for you depends on how you will drive the car, how the engine is built, what transmission you have and how tall the rear tires are.

If you are going to swap it for a 12 bolt then don't put any money into this rear end. You can locate a 12 bolt and build it or get one from a builder and have it built the way you want it. Any of the A body 12 bolt rear ends will fit your car, but there are some differences in them. The '65 and '66 rear ends have flat spring perches and the spring is held in place with a spring retainer that has a bolt through the center. The '67 to '72 rear ends have a raised center on the spring perch that holds the spring in place. The '65 to '67 rear ends are 60 inches wide over all and the '68 to '72 rear ends are 61 inches wide over all. So the '67 is all by its self with the late spring perch and the early over all width. You will have to use a 12 bolt left upper control arm or modify your 10 bolt arm to fit the 12 bolt.