My truck sags on the frint drivers side. It sits about an inch lower on the drivers side than it does on the passengers side. I have had brand new shocks put on it and also changed the coil and leaf springs that I recieved from a junkyard. But none of that seemed to fix the problem. I took it to a place to get looked at and the mechanic said the frame rail is an inch lower on the drivers side than it is on the passengers side. But he hasnt seen any indication of where the frame is bent or warped. Please help!
Shock absorbers have nothing at all to do with ride height. That is strictly a spring thing. You will find that a lot of these trucks are low on the left and nothing is bent. Most people don't even realize that ride height is important. I was the alignment specialist for nine years at a very nice Chrysler dealership up through 1999, but I never got involved in ride height problems. You might want to find an alignment specialty shop for advice. They have a lot of fixes that aren't typically known at the dealerships since they aren't needed on vehicles new enough to be in warranty.
I DID hear once that the trucks were built that way on purpose so you would be sitting level on most roads. Roads always lean to the right so rain water runs off. I'm not sure if I buy that explanation. I expect a truck to lean to the right if the road leans to the right.
Used salvage yard springs might not be the best choice either. You're just putting in what you took out. New front coil springs aren't real expensive, and I don't know this for a fact, but you might inquire about a "problem solver" set of springs that are designed to address a slight height difference, or there might be a spacer that can be added to the left side. You might also consider switching the two front springs to see if the height difference changes.
There also might be a different size steel block that goes between the rear axle tube and leaf spring. You could add a shim on the left side but I wouldn't go any thicker than 1/4" on top of the steel block and 1/4" below it because there are cast-in locating pins that fit into mating holes to keep the axle from sliding on the spring. You don't want to defeat those pins.
Adding a helper spring is also not a good idea. They don't really raise the height. They PREVENT the height from going down only when the back end is loaded down, then the uneven spring rates will cause uneven suspension travel when going over bumps. That can be very annoying.
Keep in mind that 1" difference from side-to-side isn't severe and might be within the acceptable range. It's good that you noticed it and want to correct it but the fix might get rather involved.