Re: Rear Diff gasket part number?
Actually, 8 1/2" diffs never came in Sy's or Ty's. They were originally a rear end for a full size truck, and were never put into the S/T series trucks until about.....98 or 99 (with the introduction of the ZR2 pickup. They were later put into SOME of the ZQ8/Extreme pickups. All Sy's and Ty's got the 7 1/2" diff, and the correct GM part number for the rear diff gasket is 26016661. Every GM dealer in existence should have this gasket in stock. I don't know what the Fel-Pro or any other aftermarket part number is, cause.......well, GM Parts is what I do for a living.
You'll have to forgive my rambling. I just saw the thread title with the words "part number" and I couldn't resist. It's like a mating call!