If you grab parts at the junkyard, be sure to get the GM coil and the cable which runs from it to the HEI module. That will save fuss (plug & play). Also, take the little white connector for the pickup, cutting the wires as long as possible right at the GM pickup. The other Weatherpak connector is the 12 V feed (red) and tach output (wht). Cut those wires as long as you can. I mounted the HEI on an old PC CPU finned aluminum (cut to size), but just a flat aluminum plate should work since GM just heat-sunk it to the distributor body. Smear heat paste. A good ground wire to one of the mounting screws. Might also grab the knock sensor (1-wire) & module. The sensor will screw into your block drain (as in GM). If a slant, you need a 3/8 to 1/4 NPT bushing for the drain. A Holley Commander 950 can use the knock sensor and control timing of the 8-pin HEI, as can Megasquirt (I think).