Currently rebuilding the suspension on my 86 F1 50 when I had the truck in the air the rear wheels seem to hang very low is this a sign of bad Leaf springs?

 

Bad, sprung, or broken leaf springs would likely do the opposite, imho. The way most leaf springs go bad is being overloaded causing them to break or removing the arch that's supposed to be there. This would cause them to not return to their normal shape once the load is taken off resulting in a sagging rear end. Look for rust spots, flat, S shaped, and broken leafs as indicators of bad springs.

Here's a picture as an example of bad leaf springs:
http://image.fourwheeler.com/f/37008...en_leaf_spring

 

OK thanks for the info