ClassicOldsmobile.com - View Single Post - A-body interchanging differentials?

monzaz · 04-18-2008, 09:16 AM

1964-1967 base car models all had the shorter width rears (about 59.5dum to drum)
in 1967 the olds and pontiacs in there sportier cars 442 gto etc got the wider track rears. 1" overall wider. so as long as you have the correct back spacing you will be fine example (IF YOUR RIM IS 4" BACK SPACING YOU WILL NEED TO GO TO 4 1/4" OR 4 1/2" TO PUT THE TIRE BACK INTO ITS ORIGINAL TRACKING SPOT.
1964 1965 rear had flat bolt on sping perch lands for mounting

1967 1968 etc used a pop up cone to keep the spring centered on the perch. So yes spring swap will be needed if you are using these rears . small cost to pay for a better swap.

04-18-2008, 09:16 AM	#8 (permalink)
monzaz Senior Member Join Date: Jul 2006 Location: Richfield, Oh Posts: 108	rear width 1964-1967 base car models all had the shorter width rears (about 59.5dum to drum) in 1967 the olds and pontiacs in there sportier cars 442 gto etc got the wider track rears. 1" overall wider. so as long as you have the correct back spacing you will be fine example (IF YOUR RIM IS 4" BACK SPACING YOU WILL NEED TO GO TO 4 1/4" OR 4 1/2" TO PUT THE TIRE BACK INTO ITS ORIGINAL TRACKING SPOT. 1964 1965 rear had flat bolt on sping perch lands for mounting 1967 1968 etc used a pop up cone to keep the spring centered on the perch. So yes spring swap will be needed if you are using these rears . small cost to pay for a better swap.