Bill, thanks for your comments. So maybe I haven't done enough reading on this matter... I didn't realize the "radial tubes" should only be used for special tube-type radials and that it is against regulations to use them otherwise.
All I want is a set of radial tires that will fit my 54's stock 16 inch wheels. I also thought the 215/85/r16 is the closest approximation to the bias tires I have on there now. Tall and narrow, right? Anything wider (like, say, the 225s) would be too wide for my rim I think.
My plan is to have all my "stuff" in order so I can basically tell the tire guys what I want. I don't think they have the experience that you all have, so I'd like to present them with what I want to do, rather than have them give me "suggestions". I asked some similar questions about tires a while back, but now I'm ready to actually buy something! So thanks for your input.