[jku72]

Are the rear axle control arm mounts the same between an Full size chevy and a B body pontiac? I realize I'm never going to find a good ratio for this 67 catalina, and my neighbor has a spare 12 bolt rear axle under a 67 Impala.
Can I do the switcheroo? I hate the prospect of trying to be cool with 2.73 peg leg.
It would be wierd having an axle I could actually get parts for.

[Fat Cat]

A 12 bolt can be swapped in, however Pontiac rear ends are unique and there is not one other car out there in which it's rear axle housing will just "bolt-in".

[68Prix]

The Impala uses a different mount for every control arm then the Full size Pontiacs. Also the springs are on the lower control arm on the Chevy. I am looking into having a 12 bolt from an A body modified or just going with a 9 inch Ford. I have a 12 bolt from an Impala under my GP with ladder bars if you would want to go that route. Pat

[jku72]

Hmmm, not as easy as I'd hoped, but it would still be worth it to make the mods. How did you do the change over? Any pictures by chance?

A brand new 3:55 ring and pinion costs $179, and an eaton locker only $450.

[engineer]

measure your neighbors and look under yours to see how it would work. Best since you have both available to view and measure.

[68Prix]

Like I stated I used latter bars on the 12 bolt. The lower mounts are in the correct area but are to narrow to get the Pontiac controle arms in. The upper mounts are not anything close to what you need. I will see if I got some pics of my ladder bar set up and post them. Pat

[jku72]

Interestingly enough, as soon as I got done reading these responses, I went on ebay and got a 3.23 posi for $350 bucks. I guess I was whining for nothing.