24/1 was the mix back in the day when SAE 30 was the oil of choice because there was no two cycle oil like we have today, I have seen and run the older motors on TCW 3 oil but recomended to people who own them to run one pint to 5 gal instead of six, yes it smokes more and may foul plugs faster at idle but the crank main bearings are not like modern roller bearings and a little extra oil can go a long way to keeping the older motors running strong for a long long time