Ok, I know for a fact they make 3" shackles for chevrolet trucks, they list them for 2500's, i think they are a little to long for 1500's and will hot the bottom of the bed. Has anyone here used them, I need one more inch in the rear and would love to try these. I have no problem cutting a little material to make em work.

Pics if you got em

 

I had them, and yes they hit the bottom of the bed but i drove with them fine for half a year.

 

Put em on, they'll clearence themselves seriously, a couple whacks with a 3lb should suffice.