I switched from Mobil 1 to Valvoline Racing 20-50 with the added zink. With Mobil 1 the
oil pressure ran about 30lbs. at an idle and 50-60 at 3500rpm and above. With Valvoline pressure remains approximately 55-60 lbs. at idle and 60-70 at 3500rpm and above. I really have no idea if that is all that beneficial but I think the Mobil 1 is just too thin for a high performance stroker. I still run the Mobil in my Corvette as recommended and also in my Tacoma. The pressure dosen't seem to vary near as much in those as it does in the Cobra.