Another distributor question

Forget vacuum, it "adds on" last. An engine can use considerably more advance--some up to 50-55 and more in some cases, under light load and "cruise" at highway speed.

1--Find out what your engine likes for initial

2--Find out what it wants for full power WOT

3--Subtract the two---that is CRANK degrees of mechanical advance

4--Divide by 2 to get DIST degrees, and refer to the chart. That is the length of your slots.

This whole dist/ crank thing comes from all the books and shop manuals. Just about every "spec" book I've ever read specifies distributor degrees