Norton Model 99, 99SS and late 88, 88SS Dominator Aluminium cylinder head, Cast number 22707
This cast number was used on the later heads. The earlier ones had a cast number T2225. The immediate visual difference between the heads is the extra horizontal fins between the exhaust ports.
22707 cast numbers were used from 1957.
Norton Ali cylinder head needing a good clean up.
Fins are good. . No internals but it does have the caps.