there is more body behind the axle on a burb then on a longbed pickup .
As such there is more frame behind the axle on a burb then on a longbed truck .
So, even if you could get past the body mounting issues , the frame kickup issues, and the different wheelbase issues, you would still need to add about 5" of frame to the back of the K30 frame to be able to land the rear body mounts and install the bumper
Would you not be sliding the axle 3" forward so it lines up with the Suburban wheel wells? The total frame length is what matters, no?