I have Castrol 5/30 regular oil in there now , the engine does not have any leaks it is pretty tight so would running Amsoil with 72000 miles on the car benefit me any?

 

Did the valve tap go away? Amsoil is real expensive. It's good stuff, but I don't think it's worth it if you do a cost/benefit analysis. Modern oils are so good, the real problem is keeping the oil clean. Any oil you put in there is gonna get dirty.