you might want to check the cycle magazine article on the yoshima bike, there might be figures there.
now, this might not be the answer you look for, but there's nothing holly about "official" cam card numbers, it's a starting point, you advance and retard around those numbers according to specific use (street, RR, drag...) , build, vale to piston clearance, etc.
and in any case, lobe center numbers are more important than open-close
would start with a symmetrical lobe center, say 104-104, or 105-105 or whatever that cam gives, (with a sohc your hands are tied...) and fine tune from there.
