Advance springs

I took a shot in the dark and struck out
I bought some advance springs (weren't advertised as "Mopar" but for a much older Ford) but as long as the length is alright and the tension is what I want I don't care what brand they were originally "made for".
I bought them specifically because the seller had one of each set on a ruler and I counted the wraps and measured them vs the lighter blue dot spring thats too light to do me any good and they looked mighty close by the measurement shown in the pic. But they ended up being stiffer than the stiff side spring I'm trying to replace, without the long loop of the original stuff side spring.
I don't know how to measure spring tension from a pic or a catalog, all I can go by is length and configuration.
I wonder if something could be matched up somehow from someplace like Grainger or McMaster Carr? I know id probably have to buy a box of 10 or even 20 but I ain't paying $3 a spring plus shipping again for something that won't work. The ebay seller I took a chance on had what I bought in lots of 5.
Id like to match the heavier of the 2 springs in the blue dot ones. Which is lighter than the heavy spring in the distributors I'm trying to tune.
I had 2 sets of the blue dots. I used the heavier spring out of both sets. And left the original lighter ones in place. I put one in a /6 distributor and the other one in a 318 distributor that was planned for one of my cars but I wound up "donating" the 318 one to my kid for his .. so now I gotta do one again for mine.
On a side note he needs to learn to use a timing light, he insists on doing everything by ear.
I end up getting stuck doing anything to his vehicle that involves a timing light..,... He won't listen or learn.