My 427 used Mobil 1 20-50W ,But came with instructions to not get carried away with the throttle untill the engine had at least 140°
oil temp.When the cam and lifters went south ,The oilpump 1/4" hex drive drive was about to round over.I replaced it with a blueprinted Melling hy volume pump with a 5/16" hex drive ment for trucks.The drive is 1/4" hex on the top and 5/16" hexon the lower end. I asked about the top not being as large and was told they allways round out the lower end at the pump.Admittedly my car is not an everyday driver and you do not start it unless you have something deliberate in mind.