[2blu442]

Yes, you can install a posi unit in a non-posi rear but I don't know the availability of the one that would fit your 1965 Cutlass rear end. If your not concerned about original numbers it might be easier to find a newer A-body posi rear end and swap the whole thing. I understand 64-72 will fit, the 68-72 are about an inch wider, but unless you've put big meats under the car I don't think this will be a problem. 71-72 uses the corporate 8.5 10 bolts and parts are readily available. Supercars unlimited in Portland sells new Eaton posi units, I think he has both the 68-70 and 71-72 styles available. So you've got lots of options. I've got several non-posi rear ends available for the 68-72 if you decide to get a newer housing. John