Why does my truck lean on one side?

[72gmcshorty]

I have rebuilt my frame completely. I didn't notice that it leans lower on the front drivers side. With the fenders on, the left is about 1" lower than the right side. I have new springs, shocks, spindles. I did replace one upper a-arm. Is there a difference between 1/2 ton and 3/4 ton upper A -arms? I'm not sure what size truck the one I got from the junkyard was off. I know it's the correct year though. I had a wheel alignment done without the motor in. The guy said to bring it back after it was done. Could that cause that much lean? I measured the same spot on the lower control arms and the drivers one is 1/4 lower than the other side. I have no clue as to what is wrong here. Possibly spring not installed properly? Any ideas?

[MOTHERTRUCKERS]

Before we rebuild a frame for a customer we put it on a GENESIS frame machine to make sure it has no unnoticable damage from a previous accident or rough use. It gives you a print out of all frame points. In a few cases the passenger side rail was a little sway back that we assume is from riding the shoulder of the road for years while loaded with something heavy in the bed. You will not see it in the suspension until you start putting the cab and other sheetmetal back on and then you will see a lean in the cab. Look close at the bed to cab verticle line on some trucks and you will notice the top of the bed is closer to the cab than at the bottom, sometimes new cab mounts will fix this problem and sometimes it's in the frame itself. It's money well spent in my opinion before you start putting money in a rebuild that will never be right. The upper & lower a-arms are different on 1/2 & 3/4 ton trucks, the upper cross shaft has a rounded face where the frame bolt comes through it on a 1/2 ton and requires a cupped washer the 3/4 ton has a flat face that uses a flat washer. Check your springs and make sure they are seated correctly assuming they are high quality progressive rate matched springs like TRW or EIBACH. Lower on the driver side is not usual on these frames so i'm interested in what you find out. Alignment without all parts on the truck will need to be aligned again.

[PICKMUP]

All of my trucks sit a little lower on the driver's side. I just thought it was from too many trips to McDonalds...for me, not the truck.