I am not saying to use/not use the seals,and I know why they are there but lots of early bikes do not have them and with prep they should be as good as any,if you get a gasket set now for 69/78 the head gasket is made for the seals but the gasket is used on early as well,anyway I have heard it said that these were the walmart big bore,but I aint racing so no diff.hahabillp