Thanks for the info. The previous owner had the engine and outdrive
completely rebuilt (I was told but don't know for sure). It's a 1979
Mercruiser 260. The head gasket blown with water in the oil after
less than 20 hrs of use. I wonder what could have cause that. The
engine block and manifold does look pretty new and clean for a 1979
engine. I want to do it right and don't mind spend a little extra to
replace the head and related components and hope it will be more
reliable. Can you recommend a set of head/valve/gasket/ect I can buy
outright to replace the existing potentially damaged heads. Should I
go to a Mercruiser dealer and pay full list price or get it from a
discount auto part store? Can you recommend a brand name. I really
appreciate your help.

Thanks again.