It must be OK for wet clutch, JASO-MA on the label. Good oil for cars might cause slipping clutch when they have anti friction stuff.
Quaker state Single grade (motorcycle on the label) was popular here 70's- early 80's. Castrol GTX mostly used.
There are plenty of good alternatives for you in USA.
I met a guy and his bike recently that use very cheap semi synthetic Motorcycle oil in his CB750 SOHC equipped with NOS RC stuff, 1000cc+ fed by a compressor (SU carb). He change oil every 2:nd race or so when the methanol the bike runs on is tough.