Autozone Wrong Rear Diff Gasket?

[flyme]

Rewind a few months ago when I decided I wanted to upgrade my rear axle to the 8.6". I found an axle from a GMC Denali and that all Denali's have the 5.3 L, thus the 8.6" axle as well. I bought it and when I had it apart, I counted 30 splines. The one thing I noticed was that it had the same gasket as my 8.0". The gasket was in crappy shape so I went to Autozone and and got the Fel-Pro gasket for the 8.6". When I went to put the gasket on, I noticed it was completely different size and did not fit. Thinking they gave me the wrong gasket, I used just RTV'd the differential and returned the gasket to Autozone.

Now fast forward to this past week. I was replacing my diff fluids and decided to do the rear to keep it on the same schedule as the front (not sure why, just thought it would be easier in the future) and got a gasket again from Autozone. Again the gasket was the same style as before and did not fit. Does anyone know if the Fel-Pro 8.6" gasket is for another 8.6" axle because in this forum (viewtopic.php?f=24&t=3404&hilit=8+6+axle) the gasket is the same style that was on my 8.0"?

[Trail X]

I beleive the 8.0 and 8.6 use the same gasket. Only difference between the covers is the depth.

[Moots1288]

I beleive the 8.0 and 8.6 use the same gasket. Only difference between the covers is the depth.

That is correct.

[flyme]

Thank you gentlemen.

[navigator]

I had the same issue at advance auto. I bought one for my 94 k1500 and one for the tb at different times and neither would fit the tb. I haven't tried it on the truck yet.