Front exhaust valve and guide. Some carbon buildup that cleaned up easily. Spark plugs also say fuel/air mixture is good. Maybe this is result of long term exhaust leak? Doesn't seem it would be that difficult to replace the valve guide. Any thoughts?

 

we heat the head to 250 degrees then remove and re install the guides IF they are out of round or spec

mike the valve stem and only re use if they are stainless - I only use cast iron guides and the blue rubber valve seals with the late 80 inch lower retainers

others have other ideas