In my younger days of points and condensor distributors, I took a choke cable and installed it in place of the vacuum advice. Cable knob mounted on dash. pulled out it would be full advanced. Set timing where you want it. When cable was pushed in then points plate would retard. You could do the same for reluctor plate in distributor. I did this because of alot of timing advance and alot of compression. When hot it was tough to crank over. I was 19 when I did this and thought wow what a top secret item.