case stamping on 30wt oil?

[sotxbill]

I know the (ca77) cb72 and cb77 share the same upper transmission case part number and the stamp on the case is from 1959 model year and means it was specified in 1958 or sooner.

Question is,,,,Do the early models carry the same stamping even further back or is the stamping for 20wt in cold and 30wt ND in warm a 1959 production origination on the wet sump series of engines??

What do the early dreams before that time period say??

Are they 4 stroke engines and dry sump??Or are the simply 2 stokes and need no engine oil.

Hopefully someone can shed some light on the pre ca77 and cb72 "dry sump" engines...

Thanks, Bill