Copper exhaust gaskets

I'm not familiar with the product.

What is it about them that you like? Are they reusable?

I see now that the error is mine, not Mr. Gasket's. I had looked the PN (#7166) up, found it listed for the 340...'69 even. On the package, though, the 340 is not listed, only the 273/318. I did think older 'A' block exhaust ports were all the same shape. Having never had anything BUT a 340, my experience was not the best basis for that point of view. #-o