Rally Wheel Fitment Question

I have run them for years. Also, the factory OEM 14 x 5.5 steelies work with K-H discs (because most Formula S Barracudas came this way). The wheels that DON'T fit with the K-H discs are many of the period aftermarket SBP wheels, such as slot mags or TorqueThrusts. I had some vintage TTs, and the center register hole was only bored out 1" deep, so the longer K-H hub bottomed out before the wheel mounting surface reached the hub face. The guy I bought them from had been using 1/4" spacers, but I decided I didn't like that much offset. I thought about having the centers machined out, but I wasn't convinced there was enough meat in the casting, so I sold them to a guy who was sticking with drum brakes. With the slot mags the problem isn't the center register, since they usually have an open hole with a cap — it's that on some brands the rim is too thick and interferes with the caliper.