Stall and Shift RPM Question.

I found this in the past and have used it for two distributors with accurate results. This is for stock or 'old style' MP distributors.
One Mr. Gasket advance spring will help bring the mechanical in sooner. When I initially got my car, it had two Mr. Gasket springs in it and was effectively 'locked out' since it put all the mechanical advance in at idle :/

degrees advance / slot size
12... .340
14... .355
16... .375
18... .390
20... .405
23... .420
24... .435
26... .445
28... .460
30... .475
32... .490
34... .505
36... .520