Yes - 1964-1967 have 8.2 pontiac gears. The Posi unit will also be the same and compatable too. The 1968 Model started with the Large driver side carrier bearing and Buicks own NEW designed larger pinion shaft and 8.2 ring. The AXLE BEARINGS however in the GS model were the large RW507GR which started in 1966 . That is the difference in that . The standard Skylark will still have the RW507CR. Sport WAGON had the RW507GR THis info is all according to the books BUT I seen RW507AR bearings in Wagons 65 ish Sooo This is why I always tell the guys to PULL the axle and do a physical inspection .... Never know.
EASE of posi install. This will all depend on your knowledge and common sense of a mechanical swap. If you have assembled motors and understand WHY things are torqued and why clearances are specific to rods and crank and ring gaps etc....You should not have issues with a posi swap. You will need a carrier shim kit, torque wrench, Dial indicator for backlash reading, Lock tight for the ring gear bolts. Swapping a posi for a open WITH OUT changing the ratio should be fairly EASY.... It is the ring and pinion set-up CHANGE or SWAP that would be more of a headache for most. Jim J D
i can confirm this. I had a pair of 15x8 rally wheels built for my 67 with the extra inch added to the backspacing. these wheels fit my 67 perfectly and allowed me to run 255/60/15 tires on my 67. I sold the 67 and bolted the same wheels and tires on my 65 and found that i have a rubbing problem on the inside of the tires in rear because the 65 rear is narrower.
It was a Buick only 8.2. After market support for this rear was non existent until recently, and even now, parts availability is not the greatest. Monzaz can help. If you need parts, I would contact him.
