Now that's one of the best lookin' trucks on stovebolt! Very original, looks like it just rolled off the showroom floor. The 1960 thru '66, along with the task force trucks have always been my favorite.
I've seen your thoughts on larger cast spoke tires (11R22.5) on a previous post, I think you are fine with them on the front but the clearance is not there on the rear. From what I can see by your pictures you'll need to raise the bed.
Again a great looking truck!!
James