I think these are the springs Thomas is referring to. The 72 springs can fit for the 75 since they both use the same retainers and seats. The 75 springs are slightly taller than the 72 because 1) the valves for the 75 are shorter than the 72, 2) the design of the 75 springs are different than the 72.That's my question.
I was under the impression that 72 springs wont fit the 75. At least not a direct swap.
Have you tried these majin?