Thats funny, as I have a mopar chrome box on mine, and decided to pick up a spare ignition box for the glove box. Out of curiosity, I bolted it in to see if it worked. Took it for a spin, and it was breaking up at about 5K.
Mind you these were stock OEM 1972 ignition boxes. I'm sure aftermarket did away with the additional circuitry first thing to make them compatible over a wider range.