I have seen a few advertisements for composite leaf springs, both for aftermarket lift springs/kits and for OEM replacements. The ad for oe replacement springs put the weight of a 63" chevy spring against the weight of the composite spring. The oe spring was 69 lbs, and the replacement composite was 31 lbs. Here's the website of the manufacturer: http://www.liteflexllc.com/arvinmeritor.html They say that the fatigue life is 3 1/2 times greater than steel, but I wonder if they considered max compression and droop in that equation. What does everyone think of these?