Originally Posted by williamwilliam

Do you have stock springs on your truck? I always thought that was the reason a helper spring was installed on f100's was to help control the springs from flattening out during heavy loads and to also make sure that the upper leaf springs retain their natural arc?? Ive never seen a stock spring setup lay flat, no matter how old the truck was. I know of 2 other trucks in my area that also used the same setup as mine and 2 sit the same, the other one is running a smaller size tire and also used a 2 inch drop lowering Eibach coil spring in the front so naturally he's lower.......

I can see where you are coming from I guess, Ive just never saw a stock suspension truck sag in the back. I have seen a truck completely sag all the way down bottoming out the truck in the front (literally sitting on the stops) but that was because the owner heated the coil springs to lower the front a little bit and eventually became weak after several years and gave way. He came out one morning and his truck was sitting on the front tires, LOL.