My 1968 Cougar had W code 427 and BF 32 Autolite spark plugs. I poked around in town and it ran better with BF42 plugs. If you have electronic ignition, either should work. My old FE had points.
Oil is so much better, I would not recommend anything. There were no synthetics 40 years ago. Everybody, including me, wants
zinc and phosphorus.