Can't really do it at home.
The spacing between degree marks are dependant on the diameter of the balancer. The larger the diameter the wider the spaces. I can't see how the degree tapes you can buy are accurate on different size balancers.
To do it accurately the balancer needs to be pulled and scribed while in a dividing head.

Ferret Instruments makes them for SnapOn. I went to Napa and bought the Ferret less than half what it was on the Snapon truck

I bought a Ferret 84 yesterday!
Haven't tried it on MSD yet, but it worked great on a Thunderbolt IV.

Does anyone know if it works on MSD?

Thats the same one I have and it works on MSD ,both my cars and the Hustler Ive use it on no problems

Thanks Rob!

So, are you guys saying the Craftsman lights are crap? Or, are they just inaccurate with MSD type ignition?

I borrowed a friends craftsman adjustable light and a snap on adjustable light. Put both lights on the same motor and they read the same. I set the total timing at 3000 rpm, not the base timing. That should eliminate the multiple spark issue from the Crane HI-6M

I have used a sears light for 20 years the same light and it looks it . and works great. mds says to not use dial back lights as this was said before . I guess use what ever works best for who ever.

Like you said...
IMO those that run into problems with an adjustable light and MSDīs donīt set their timing at 3000+rpm.