I can't answer your specific question, but I'm restoring a 53 3/4 myself. I'm staying with the stock 15" wheels. On the other hand larger rear wheels will certainly give you somewhat better cruising speed. Radials are good, but could be put them on the stock wheels. Or, you might look at a stock 16" or 17" wheels with the moons and radials.
As you say, the why's and whynot's of this issue have been covered before
. I hope you get a variety of comments on this topic. It's always interesting to hear how other folks tackle any given project on our 'bolts. If you do implement your vision, be sure to post some pics of the before and after somewhere on the 'web and give us the link. And if you do make the change, be sure to sell your old ones over in the Swap Meet, for folks like me that can always use some stock wheels.
