Does anyone know how aluminum cylinder heads are date coded? I looked in Colvin's book and it didn't seem to give a clear example. The only two codes that looked like they could be date codes do not follow the 'letter-number-number' configuration of cast iron cyl head date codes.
Pictures of the Camaro's cylinder heads follow here...
Left cyl head
The code in this next picture reads upside down, and looks to me like '589'
