prestolite distributor gasket

jazak5 said
any one know the proper size of the O- ring all I could find is the paper gasket that goes under the ditributor base not the O ring that is in the grove. 1968 340

View attachment 1715288750

Here is what i used on my 70 340 prestolite dual point.I also bought them from amazon as well.
https://www.amazon.com/gp/product/B000FN0TVC/?tag=joeychgo-20
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