I agree with Terry about contacting the tire dealer. In my experience, I had K-H wires on my '60 Imperial and kept losing air. I installed tubes and a few miles later lost a tube due to it rubbing on the end of the spokes (inside the wheel). Off came the tires to install wheel liners and new tubes, never another problem. My Darrin and '57 T-bird have K-H wires, liners and tubes with non Coker bias ply tires, I have never lost any air. If you insist on using radials it is my opinion that you should use radial tubes and don't forget the liners. Also with radials, you should have the alignment "tweeked" and get a second opinion on whether radials are OK to use safely on the old style wheels, I once rolled one off a front wheel on one of my Amphicars.
Gary.