Jerry, please correct me if I'm wrong.
But, I believe the only cam bearing surface on the cam that does not slide through at least one of the cam bearing in the block is the last one nearest the gear. Thus my thought that that bearing surface on the cam may have been milled a little larger (mic the surface to be sure). As he said it got really really tight as it went into the last one.
Two possibilities;
1). The cam bearing surface was milled wrong (as all others slid in easy except the last)
2). Bent cam (again at last bearing surface)
While it is possible for the cam to be bent it is unlikely, however rare, it is likely to get a surface milled incorrectly. Thus my suggestion to mic the last surface on the cam.