O-Rings on distributor drive shaft

Guys,
when I removed my distributor ( LT1 engine)  to check its condition along with the replacement of the water pump I found two O-Rings on its shaft, plugged into the front end of the camshaft. I  don´t know what they should seal, the camshaft has no oil inside and is sealed to the outside housing with a usual sealer ring. The O-Rings are hardened and brittled, I removed the debris, but don´t know at all what function they have. They aren´t available from Rockauto as spare, so I´ve to look after them over her in Germany. ID is about 10 mm. Could it be that they should only "stabilise" the distributor driveshaft inside the cam to prevent it from vibrating ? The distributor is in nice condition so I don´t need a new one what might have included new O-Rings on it. In the manual, nothing is refering to these O-Rings. Thanks for advice

They wouldn't be there if they weren't needed. They stabilize the shaft and cut down vibrations.

The GM part number is 10474278 but they are discontinued.

You need to get a timing cover gasket set from Fel Pro.

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Thanks, thats exactly what I supposed. Of course it´s necessary, but not for sealing. Supposedly nobody knows the dimensiones of the O-Rings to source them in Germany? I wouldn´t order them from USA to Germany, would be a bit strange, just 2 O-rings.....

In the USA, we have hardware stores that sell all different sizes of o'rings. Measure and match up something.

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Post #15, says the felpro timing cover gasket kit has them in the package.

Hi, got some with the right size. Have it got fixed already, distributor back home again, thanks !