[dap930]

Bobby,

It appears in the photos that one or more of the exhaust rocker are shafts are leaking into the area where the spark plug(s) (the engine is twin plugged?). The rocker arm shaft is held in place by tightening a through bolt that causes the conical end washers to expand the rocker shaft ends against the rocker shaft bore in the cam housing. If the rocker arm shaft loosens, it looses the seal in the cam housing and a small amount of oil will leak from the shaft bore down into the spark plug cavity and will find its way to the bottom of the head where it looks like the head/cam housing joint is leaking. I had this problem on my '77 which was due to a broken rocker arm shaft. Also, I installed RSR seals on the lower (exhaust) rocker arms to prevent further leaks.