Hi all, Hope you people can help me out, I am out of options.  I have a 1957 Ranchero I am trying to rebuild.  Have the body off the frame and the frame completely stripped down.  Took the rear end completely apart.  Ordered a small bearing disk brake conversion from Summit.  OK. Starting to put it back together and the gasket I have for a ford 9" won't even come close to fitting.  I took the housing to a well known differential shop and he says it is not a ford 9" and he has never seen one like this.  Called Summit back and asked of if the disk brake conversion will fit.  After an hour on the phone, they were great, sending pictures back and forth Summit says it is a 8.75" rear end.  The disk brake conversion will fit.  Horray!!  Except now I cannot find a gasket for a 8.75" read end.  Any idea what rear end this is?  Thanks for your help

According to google the 8.75" rearend can be replaced by a 9" carrier.  If it is indeed a 8.75" carrier the gasket for a 9" carrier should fit.  The stock rearend for a Ranchero, IIRC, is a big bearing same as the station wagons and Couriers.

Thank you for your reply.  A stock 9" gasket will not fit, already tried it and the rear end is indeed a small bearing rear end.

  Looks like you have a late 50's early 60's Oldsmobile or Pontiac rear axle. Don't know too much about them other than hot rodders back in the day used to swap them in now and again.

https://www.google.ca/url?sa=i&url=https%3A%2F%2Ffabcraftmetalworks.com%2Fproduct%2Frear-axlera6-0510%2F&psig=AOvVaw2yy5K7Ipr9Ml-gH9NnNANg&ust=1747836791068000&source=images&cd=vfe&opi=89978449&ved=0CBgQ3YkBahcKEwiwwrPPnbKNAxUAAAAAHQAAAAAQIQ 

Seems that there was a yard in Colorado near you that had some '57 cars. Rich mentioned it if I am correct. He may know where it is and you can see if they have a 9" still.

Terry.  Not that hard to make a gasket or to just use silicone that will never leak.

Are there axles with it if so are they Ford car bolt pattern 5 on 4-1/2.

I agree with Randy, that sure looks like the early Oldsmobile rearend. If it is, very doubtful that the Ford disc brake kit, or anything else from a Ford 9" will fit.