if you do, i had the same problem, the only way is to re-torque all the bolts, also check the bushings on the leafs, because they are old and cheap, mine were really cracked, but most of the squeaking is from the block moving on the leafs, make sure especially to re-torque the U-bolts, try to use a torque wrench, and if your using nylon nuts, check them they tend to back up (they get old)
Check your U bolt nuts right now! If they are loose you are driving a death trap and nothing sucks like a funeral! Especially when it is your own. Then if everything else looks cool get a can of spray lithium grease (you can't use this in place of your lithium pills, I tried and it doesn't work!) and spray some on the shackles and into the bushings as good as you can. If this doesn't help you are beyond my limited experience.