Really depends if the engine has a metal or graphite version. I have no luck in getting those graphite head gaskets off without some damage.
Could even be a badly worn valve guide...I have seen many 3.5-4hp Briggs that smoked to be just a worn out valve guide instead of rings and/or cylinders.
Don't remember what the valve stem size is but it is 1/4" version should be able to ream and install a new guide if needed. For me I can no longer get the aftermarket valve guides I once could so it is back to the Briggs ones.
