Searching for a posi rear for 1968 Oldsmobile 98 coupe. Please help?
April 26th, 2018, 05:28 AM
#2
Moderator
Join Date: Jul 2007
Location: Edmond, OK
Posts: 15,890
Jorge, a Vista Cruiser differential won't fit your 68 98. You need a differential from a 98 or Delta 88. I'm not sure if a differential from a Buick Electra, Chevy Impala or Pontiac Bonneville will work. Unfortunately, these are quite rare. From time to time one of our members; monzaz, has one for sale. Good luck in your search.
April 26th, 2018, 07:37 AM
#3
Old(s) Fart
Join Date: Mar 2007
Location: Northern VA
Posts: 47,300
Your Ninety Eight could have either a Pontiac 8.875" axle (NOT to be confused with the Chevy 12-bolt) or a Type O 9.3" axle. The Pontiac has a ten bolt cover and twelve bolt ring gear. The Type O has a twelve bolt cover and twelve bolt ring gear. Fabcraft Metalworks sells new posi units for the Pontiac axle. No one makes new posi units for the 9.3" Type O (this is NOT the same as a Cutlass Type O). Finding a used one is your only option for that axle. Most 1968 Ninety Eights got the Type O.
April 26th, 2018, 06:18 PM
#4
Registered User
Join Date: Apr 2018
Location: Cobleskill NY 12043
Posts: 83
Your Ninety Eight could have either a Pontiac 8.875" axle (NOT to be confused with the Chevy 12-bolt) or a Type O 9.3" axle. The Pontiac has a ten bolt cover and twelve bolt ring gear. The Type O has a twelve bolt cover and twelve bolt ring gear. Fabcraft Metalworks sells new posi units for the Pontiac axle. No one makes new posi units for the 9.3" Type O (this is NOT the same as a Cutlass Type O). Finding a used one is your only option for that axle. Most 1968 Ninety Eights got the Type O.
Thread
Thread Starter
Forum
Replies
Last Post
nj_cutlass72
Parts For Sale
4
November 20th, 2019 09:11 PM
70sgeek
General Questions
2
April 7th, 2018 07:14 AM
69OldsCutlassS
Drivetrain/Differentials
6
September 9th, 2009 01:05 PM
