Problems engaging in 4x4

[jcnalley]

I recently picked up a 96 Chevy extended cab. The previous owner did a straight axle conversion. The truck has a 6" suspension lift and a 3" body lift. The problem I'm having is the truck will not engage in 4 wheel drive. Is it possible that the opening in the floorboard for the transfer shifter is not big enough due to the 3" body lift? Could the shifter be hitting the floorboard before it fully engages in 4 wheel drive? If so, I should be able to adjust the linkage to compensate for it. Anyone have any suggestions, or similar problems? Here are a couple of pictures of my truck.