My 57 sets too low in the rear, and it doesn't take much payload to settle the fenders down onto the tires, so I need new springs. I have checked prices from several parts suppliers, whom we all know and love, plus my local spring shop, and found prices from $300 to $688 per pair. None of these sources described the springs in any way to suggest that theirs were superior to or more economical than anyone else's. What should I look for, or what questions should I ask, to determine what I am getting for my money?