I don't think the distance from spring to the bottoming bumper is specified, but if your springs are dead flat they may be weak [but still ok], my fronts show a very slight arch

Bill

Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics