These are hard to find these days. $25 and shipping. Package not included. I have several more in the package and I am keeping them in it.

 

I suppose you mean the GM part as the Fel Pro RDS55008 gasket is readily available just about everywhere.

 

That is not the correct gasket if you have wet bearings on the axles. Would be ok with the sealed bearings. I know people get away with the wrong gasket or no gasket at all and use RTV but this is the only correct gasket for an O type and wet axle bearings.

 

Sold

 

So the'70 differential cover gasket is different than the earlier ones. Is it the oil feed hole on either side near the axle tubes that is different on the gasket?

I never realized there was a difference and I have no idea which style is on my O-Type.

 

When I get home I will see if I have some pictures but yes. The best I understand is that the oil is directed into the feed holes better like this. I know on the W-27 they crudely cut channels into the aluminum to allow oil to flow where the upward hook on this gasket is. I know people do it with RTV all the time but not sure if it would have long term affects or not. I assume it would have less oil flow to the axle tubes but I am not an expert. I just use these gaskets and not worry about it.

 

Seems like I remember the 71-up 10 bolt rears have similar feed holes and the cover gasket seals around them. I suppose they have the same (or similar) oiling system as the '70 O-Type.

 

Not all of the 71/72 10-bolt 8.5" rears had the lubrication holes, only the Olds housings had them - the Buick housings that were installed in 71/72 Cutlass and 442 models assembled at the Texas and California plants did not have them.