Well the only reason I'm questioning it is because the front sits perfectly level and the truck almost twists from the front to the back

Well looks like these trucks have been leaning cuz of the gas tank putting more weight on the driver side. Some guys have recommended re-arching the leaf springs in the back to fix this. After re-arching then they said adding rear leaf helpers to stiffen up the rear to prevent the "Chevy Lean" as they call it. Lol

Just find you a BIG girlfriend and it will even things out!

have you checked the body mounts yet?

Body mounts should only make the cab sit crooked.

Well, considering how none of the leafs are broken, I think I'm probably just gonna go ahead and get the driver side re-arched (3/4 ton springs are not cheap). If it ends up making the driver side sit a little higher, I don't care cuz it's thanksgiving!

Good luck brother. The last spring I bought was for a F250 and it was $150 from the junk yard. It was a 1999 and all but the main spring was cracked in half. Talk about sitting lower on the drivers side!

my truck is crooked
 

I put a leveling kit on my truck and now the back end is crooked. I looked at my leaf springs and they are fine. Any tips on this?thanks

If you have the same height on both sides up front, as you say, then it is not a front coil spring issue. By your own measurements the rear has the issue. It is common to have leaf springs get weak and especially on the drivers side as that side always has a person in the seat and is usually where the gas tank is, thus more weight on that side. You can buy a new set of springs, go to a junk yard and get a set or a side or add a leaf to just the weak side. It all depends on how much you want to spend. The junk yard deal could be just replacing a weak set with another weak set, you won't know until it's installed. You could take it to a place that will re-arch the springs and see what they say.