Copper/steel Payen head gasket. Suitable for all large bore modified engines. 3.4cc compressed volume. THE standard for years has been the cooper head gasket for an A-Series motor. The most commonly used had been this "AF460" designated version. The first of them actually had an asbestos inner core. The modern AF460 now has a environmentally friendly version (the GEG300), but it's still the famous "Copper Head gasket"