Or maybe a lifter tube seal? Damn, that Road King of yours is nice, Jeff.

 

Could you have a pushrod tube o-ring leaking, or one just not seated correctly?

 

It is more than likely a gasket. Before pulling heads, run a compression test, it is a lot easier. A little pressure in the engine block will cause the bubbles, nothing to worry about.

 

Check the lower gaskets on the push-rod tubes, the spring in the push-rod tubes as the do weaken over time especially if they've been removed a few times. Then do the compression test with a warm engine and the throttle held open, if you have a low cylinder put some oil in that cylinder and repeat it. If the compression goes up then you probably have a ring seal problem. A properly done leak-down test would definetly help pinpoint the problem.