@Noobz347 The spacer idea may still be workable, but I discovered another issue while looking into it. These older Draglites use long shank-style lug nuts, and with the proper single washer the shanks protrude past the rear mounting surface of the wheel and bottom against the rotor before the wheel clamps. A spacer thick enough to address that and clear the banjo bolt would need to be properly made for the application, and I would also need longer wheel studs.
A 3/16-inch spacer might solve both clearance problems, but it would also move the slick outward by 3/16 inch. I have not purchased the slick yet, so I cannot mount the complete package and determine whether that new position will actually fit under the car. There is not much spare room with a 10-inch wheel under a Fox, and I do not want to order a custom spacer, longer studs, and tires only to discover that the combination rubs somewhere else.
At this point I am probably better off selling these for a little more than I paid and looking for a wheel that clears the banjo bolt, seats squarely without a spacer, has the correct lug hardware, and works with my existing roughly 1.5-inch studs. It may cost more up front, but I do not want to keep chasing custom solutions to make a $275 pair of wheels work. This definitely did not become the budget drag-wheel setup I imagined.
@KRUISR I updated the link to a better post that covers the rotor sizes.
Ps. I stripped the rear interior down and got the car to a chassis guy to weld in Battle Boxes, install new WBO2 bungs a bit farther back while clearing the stifflers D/S safety loop, and see if he can do any kind of welding to seal the leaking $1k-to-replace Ron Davis radiator. It's a minor leak, but obviously it's preventing the cooling system from pressurizing, even if it still does a fine job of keeping everything cool.