Seeing that old can reminded me of my dad changing his oil back in the 50's. That was all he used but in the 10w-30 flavor. As I recall he got well over 200,000 mi in his 55 pontiac before he overhauled it - not too bad I guess for back then!
LOL I just used some Valvoline 30wt non detergent oil, SB for my power washer pump. It calls for a non detergent 30 wt oil, this old stuff fits the bill for me.