In an on going "war of words" with a friend about "our" engine vs the Chebie engine, the subject of G.M. having Positrac, came up. I believe Ford & also Chryler, introduced limited slip differentials later than G.M. But, I couldn't come up with dates. For instance, did 57 Chebies have them available as a "stock" option?  

Paul

I have a "factory" Traction Loc unit in my 56 Victoria rear end. So we are at least one year up to start! Chuck in NH

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

I've seen '55 limited slip rears in several fords

       A  L  A  N   F  R  A  K  E  S   ~  Tulsa, OK    

I would be suprised if they wern't an option in the 49 and later. Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Paul,

         I don't think limited slip or positraction was introduced by GM until aroud 57. I do know the '58's had it, didn't really work very well. I beleive the '58's had a newer style rear end as well. 

Frank/Rebop

Bristol, In ( by Elkhart) 

Positraction was an option on 57 Vette's,not on passenger cars until 58.I'm almost positive Ford didn't offer any kind of limited slip or locker until 60 or 61.They certainly did not offer one before 58.

 

Paul,

Boonville,MO

Would you like to see one! As I said before I have one in my 56 Victoria STOCK rear end. It's a ratchet lock simular to the 60's Mustangs. Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Ford did not install any kind of locker or limited slip in any cars before 58 at the earliest,and probably not until 61.If you have a 56 with a locker,it was installed after it left the factory.

 

Paul,

Boonville,MO

Interesting arguments, gentlemen!  Personally, I've never seen or heard of a 55 or 56 Ford that had a stock limited slip rear. But, getting back to G.M.'s Positrac, would the 57 Vette setup fit a 57 sedan?.. The point I'm trying to get at is that I strongly suspect that some of the vaunted performances of 57 Chebies (real or imagined) may have been assisted by having limited slip rear ends, at some point, that their competitors did not have, whether legal or not... Remember, stock class 57 Chebies somehow in the hands of the omnipotent NHRA, became legal with 4 speed transmissions at some point in the early 60s. Even though none ever came from the factory that way!   

Paul

Sorry about the duplication, tired, past time to go to bed I guess... 

Paul