I have a 1967 SS 396, My question is: When I put my axels back in and button everything up, What kind of gear oil should I put in? I have a 373 posi rear-end in it.

I used 85W90 from Carquest with 1 bottle of the GM posi additive.
Jody

What type of posi carrier are you running? Some manufacturers recommend specific lube. Check with them. Auburn for instance does not recommend synthetic lube, but exactly what jodysss396 uses.

I'm not sure what type of posi unit I have, I bought the car in Oct and am slowly learning what has been done to the car. The reson I'm asking is because I actuallt had this place do some work for me and the stuck this 85-140 gear oil in there. I drove the car home (12 miles) and parked it in my garage. I had a feeling it might be the wrong gear oil and my Dad had told me that he wasn't sure but he thought there might be a posi additive for it like Jody said.

I just installed a new Eaton posi in mine. I can't give you a report yet because I'm not finished with the rest of the underbody. Soon I'll have her back on the road.
Jody

Jodi,
I just found out from Tom's differential to use 85-140w and depending on if you have a new posi or a exisiting one you add 1 to 2 (For new units) bottles of that posi additive.