I used the Wildwood cable-operated spot-brakes meant for go-karts, in my installation. You'll need to fab a braket for the calipers ton slide back & forth, as you say, and the calipers are designed for 0.810-thick rotors. If your JFZs are 1.25" thick, you'll also need to make a pair of caliper-spacers to widen them. I wrote an article in the Aug '98 POCA news on this adaption, with photos. In retrospect, they don't work any better than the stockers although they're only 1/4 the unsprung weight. They also rattle a little. I'll probably address this issue again, from another angle, when my new shop is finished.
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