rather spend time & money on 57-58 P/O 9.3 then my 56 unit. can any one tell me if 57-58 rr will fit in my 56 88 post, drum to drum width first,&second perch to perch? with exception to driveshaft &u-joint mods. I believe 59 & later are to wide espec. pont. +leaf to coil mounts may differ any imput would be greatly appreciated!

 

Sorry, I can't answer your question. But if nobody replies to this post with an answer contact a member named monzaz. Jim is a resident expert with rear differentials.

John

 

If your looking for specs for this rear, go to fabcraft metalworks. They just put out a good '57-'64 Pontiac/Olds rear end guide with measurements and other info about them. It might be a good investment before you jump into the swap

 

thanks 59, just got the bible (57-64 P/O 9.3) from fabcraft pretty cool & informitive but does not have housing dimensions.

 

Hi Marsman. Sorry i'm a little late w/the dimensions i promised. I will have the rear-end width dimensions from my '57 olds tomorrow and will post. Things have just gotten in the way. Bill. WFG4U@aol.com.

 

Olds 57 58 are the narrowest of the Gasser rears.
Ponitac was always slightly wider... WIDE track commercial stuff.

29.25 was the shortest of the axle shafts. so x2 by 2 and ad about 1" and you will get a usable width.

58.5 + 1" 59.5 about the width of a 67-69 camaro or Nova 68-72

Jim
J D Race

 

Hi Marsman. Just measured my '57 olds rear end. Housing Flanges are 54 1/4" w/o backing plates or anything attached. Overall width with axles, drums, backing plates, etc. is 59 1/4" overall measured from the outside of the drums. Hope this helps. Good luck.