I have seen the 52" front spring subject beat to death. After helping my buddy swap in 54's into his truck, I feel confident that I have ample knowledge on that. I am planning to swap my 52's off the back of my 1986 K5 into the front and install something longer into the rear. I was thinking of a ORD shackle flip along with their heavy duty shackles. I have a local Pick-N-Pull that has a good supply of full size trucks, Suburbans, and Blazers that I can pilage parts from. What are my best options? I think I read on here somewhere and correct me if I am wrong,but the older 54" springs haveing a slightly higher load rate, which would last longer (take longer to sag). I may even be up to 64"er's?? What models and years would I find these in? Will all of these spring options fit in the stock locations with ORD shackle flip, or will I need to move the mounts for or aft. Would longer shackles help? Ideally I would like my axle to sit in the stock location or aft of center.