So, I completed the underside of the cab yesterday and mounted it on the completed chassis. It fits OK. I had a 1/8" shim under the right front mounting point in order to get the proper 1.83" clearance from frame dimension. Doing so also solve the problem of the left rear of the cab being more than .76" from frame to mount bracket. In other words, it solved the "rocking" problem. Measuring rear cab cutout sides from frame, I am just least than 1/4" difference from one side to the other. Can't get any closer without enlarging front mount hole in frame.
So, the door does not even fit within the opening, so a bit more than 1/4" too large. Very consistent all the way from bottom of door to belt line. Door is even tight at the window frame in places. After reading Deve's responses, I imagine it is possible the PO replaced the door at some point. I vaguely remember the door not closing properly when I purchased the truck. I will give Jim Carter's a call to inquire about a replacement door, but may give it shot in modifying what I have. If JC has a door, at a reasonable cost, I have nothing to lose in trying (other than my time). I just cannot see how it is a cab related issue. But, the opening is smaller than the other side which makes it seem a cab issue.
I am concerned that if I size the door to the opening, then the rubber door seal will be a very tight fit and make closing the door difficult when complete.
BTW, the cab looks good sitting on the chassis (instead of on block on top of chassis). I still have lots of prep work to do on the cab before painting, but getting closer. And, I have to ensure good door fit before painting cab. Thanks for all the reply's
