For Oil, we've used Mobil 1 15W-50 in my father's 87 GN since new. I changed over from Valvoline 10W30 in mine to Mobil 1 15W-50, maybe not the best idea to change oils, but my engine is happy. Mobil 1 synthetics are good enough for me! The 15W-50 variety is specifically for older valetrain...