The width of the front cam bearing journal has absolutely nothing to do with it. What matters is the distance from the front of that journal to the back of the gear when installed, compared to the thickness of the thrust plate. You have already (more than once) determined that that distance (set by the thickness of the spacer) is .006" more than the thickness of the plate.
The problem appears obvious to me - the upper bolt on the thrust plate has an overly thick head or is not seated properly against the plate, and the backside of the gear is rubbing on it. When you tighten the gear retaining bolt, the gear contacts the bolt head, which prevents the gear and shaft from moving back, and at the same time pulls the camshaft forward against the thrust plate, which prevents it from moving any further forward. Hence, your ".000" end float. Try turning the camshaft and gear until that bolt aligns with one of the holes in the gear, and see if you have end float then. BW