I am doing the same thing on a 31 WBCC. Generally the key for me was that the block under the front door post needed three pads and the two rear ones one pad. Tightening the rear body bolt first, then the one in front of the seat riser next, then skip to the firewall bolt. Needed two pads here and you need to tighten it until the door mouldings line up. Then secure the door post bolt and adjust the front bolt if needed. All the while you need to check the hood fit against the firewall. This requires that the gas tank be in place and the cowl moulding be in place too, or at least for me. There is some movement of the cab side to side to help with the hood fit but the radiator didn't have much movement in my case. I tightened and loosened the bolts several times to get it to where I am now.
One thing that I was bothered by at first is the clearance between the bottom of the cab and the splash apron. I ended up with less than 3/8" and I can't get it much lower or the pan under the seat riser will be on the frame.
Another thing that surprised me was that the triangular body bracket on the outside of the frame only catches the rear of the two body bolts at the door post. Thought it should catch both (as on other of my cars) but everything else fits so that's the way it is! The front of these two bolts goes through a hole in the splash apron and doesn't secure anything even with a big washer.
