Join Date: Dec 2012
Location: Gastonia, NC - Born & raised in Connecticut - 31 years
Mentioned: 1 Post(s)
Tagged: 1 Thread(s)
Quoted: 404 Post(s)
Pontiac did not add the rear anti-roll bar until the 1970 model. You have a 1968, so either yours has been added on to the original rear, or the rear end has been swapped to include the sway bar set-up.
68GTO4004sp provided the link you need to identify a Pontiac rear. Find the axle code on the axle tube as noted in the article. The numbers you provided may simply be part numbers or even foundry numbers. Get a copy of your car's build sheet from PHS services which will help identify the original rear end as well as all other codes, parts & options.