Years ago I bought a set of these gaskets because I needed the extra space under a low profile set of valve covers I was running for roller rockers. That first set of gaskets lasted decades. In the years after, I have collected a dozen sets of gaskets from overhaul sets, valve job sets, and I figure I have saved hundreds of dollars using three or four sets just like these. This has been a very good find for me and my old big block Camaro.