ASPC what you are going to have to do is put the oil analysis charts away and go with the folks who have used the oil GN4 for decades and decades. Only you can make that choice of which oil will protect your machine best. We can only give you our take or opinion and experience. Some here that hate the oil will hate it and say its no good even though the oil has proven it will protect your motor for 8K miles. It has beaten all new comers botique oils and diesel oils .It still is the heavy weight champion of oil. 
