distributor springs light enough ??

still working on getting the correct springs for the weights on the dist.
I have several sb point and electronic distributors . parts donars

I'm looking at the springs inside and the lighter of the springs is usually about 10-13 coils . which would be the lighter spring on tension ? They look so similar . what is the "rule of thumb" on the spring tensions?.....is it more coils the less tension weaker the spring or less coils the more tension /stiffer ?..

I have another spring out of a BB mopar dist and it is shorter in length and less coils (7) appears to be a really weak spring. thinking about using that one. maybe it's an aftermarket spring kit .
someone mentioned a mr. gasket spring kit works Good.
Thanks guys !

john