View Full Version : 10-bolt rear end on 71 455 GS?

John Hutchin
06-19-2011, 11:17 AM
Hi all,

Did the 71 GS 455 ever come with a 10-bolt rear end? Also, does anyone know if the wheel cylinders are any different on a 12-bolt rear end compared to a 10 bolt?


64 Hardtop
06-19-2011, 02:06 PM
10 Bolt rears are a yes in 71 GS.
I believe the rear wheel cylinders are the same for several years 10 or 12 bolt. Not certain though!

06-22-2011, 10:42 PM

71 Skylarks and GS's came with the 8.5 inch corporate ten bolt.

06-22-2011, 11:02 PM
Didn't the GS's built for Canada have the 12 bolt rears?

06-23-2011, 09:25 AM
68-70 Canadian built Special/Skylark/GS usually came with the 12 bolt. Currently I have a 69 Special Deluxe that has a 2.56 12 bolt. Have seen GS's that had 12 bolts too, mostly 68/69. As to wheel cylinders, the 7/8" rear wheel cylinders were all the same basically after 67 (some 64-67 used 15/16") up to the 80's. WC45873 is a common part number (that is a wagner p/n) and is shared by other manufacturers.
There were some differences to the Buick "Canadian" 12 bolt such as the pinion yoke (used larger U joints), axels and backing plates. The drivers side upper control arms were different than 10 bolt ones. One side was shorter and had a tack welded support. This was done as the 8 7/8" housing rubbed on the 10 arms. Yes, the 10 bolt arms can be forced on, but either the arm will wear of cut a grove in the housing.
Probably more information than you wanted. :)

John Hutchin
06-23-2011, 12:06 PM
Thanks everyone for the replies! I've been out of town all week or I'd have replied sooner. Mark, that's definitely the information I was looking for... thanks for the part number as well!
Best regards,