Engine Break-in - How to measure rpms with Helmet Dist?

[Ziggster]

I should soon be ready to start my rebuilt C59A and was wondering what methods are available to measure engine rpms so I can break-in the cam at 2,000 - 2,200 rpm? I have a helmet style distributor installed. I have a marine tach, but it will need some type of “board” made to make it work. I do have a timing light as well, but not sure if it will work on the flathead to measure the rpm.