I have that same dizzy.
Mine has mechanical advance.
Does the rotor turn by hand about 1/8th of a turn? Mine does.
I set mine about 14* @ idle, then its ~ 34* at 3000+ (14* initial, +~20*mechanical)
No dial back timing light here, i just marked the balancer when I degree'd the cam @ 30* and 35* (saw blade & white paint, like oem)
I have also set it with the tach while underway, too
Good luck
Dan'l