Please use efi's instructions. The use of any of the diesel oils is a better place to start and in my opinon continue. They will soon loose more of their zinc content also but it's the best now out there. On my inlines I also use GM EOS on everything and poor the rest of the bottle down the push rods before putting on the valve cover. Good Luck


216.158 MPH 12-Port 302 GMC on 70% 171.0 MPH 302 stock head on gasoline 7 years later