[roostertoo]

I personally don't like blocks. I have installed several lift kits on 4 X 4s that used blocks but I'd rather add leaves, buy custom springs built to size, or extend the spring hangers. I also wouldn't pull any measurements from the rear wheel well b/c you said your going to install the original style bed so the wheel wells will not match. I'd pull all measurements from the frame to the ground in relation to the bed that you are going to put on the truck or do the bed swap first. If you do the bed swap first and then adjust your ride height, you can "mock" everything up before it's finalized.