Now that the 455 is up and running I need to keep the power to the ground. Can someone give me a hint on where to find a Posi unit for the 57 rearend. I'm thinking good crusing gears with a ratio maybe 3:08 or somewere in that range. Currently running someware aroud 2:73-79

 

The cheap answer would be traction bars because people are getting INSANE prices on '57 - '64 POSI center sections. I've seen used center section assemblies on Ebay go for $700 and up. If youre searching for a posi center section dont limit yourself to just Olds....Pontiac had the same rear. Heres one more thing youll love - Dont quote me, but I'm 60% sure the posi center section took a different numbered splined axle depending what year it was. ( wheres Norm when you need him?) Your best bet would be try the junkyards and hope the guys dont know the going price for them

 

Not ready to talk about Chevrolet (Posi = Positraction) differentials, on an Olds site.

Pontiac manufactured the rear ends, drum to drum, that were used by both divisions.

Limited slip diffs were called "Anti-spin" by Oldsmobile and "Safe-T-Track" by Pontiac.

'57-'58 used 28 splines, '59-'64 used 31 splines.

Norm