My question is if you have a 10" 500lb spring over a 16" 500lb spring and then I change to a 12" 500lb spring over a 14" 500lbs spring what is the diffrence in changing the spring length but not the sping weight? Does this make since?

Your better when both springs are closer to the same length. They work just about the same. With the that old set up, the 10incher would end up bottoming out on itself earlier in the stroke, leaving you with a stiffer ride after that through the remainder of the stroke!

isn't that typically the reason for dual-rate coils? for more bottoming resistance further into the compression?

your ride would not be affected, because your primary rate remains the same...but like poundsand said, you'll hit the secondary rate earlier.

You are going to get many opinion and it is going to get confusing but to answer your qustion, none. As long as your upper or lower spring dont coil bind there is no difference. If your "splitter" contacts the collar before your upper spring binds and your shock/ bump stop bottoms out before your lower spring binds it doesnt matter.

Call your shock manufacture. King, Fox or whoever you have. I have always found them helpful and they should have the right answer.

Thank you for the info. I talked with fox and was told just about the same thing as what you guys have said. As long as you dont shorten your bottom spring to less than what the emulsion of your shock you will be fine.