MSD ign module for HEI
MSD #83645 module. It switches 7.5 amps for a hotter spark v 5.5 amps for the stock module.
This module has a built in rev limiter, simply adjusted with a dial: 5000-10,000 rpm. According to the instruction sheet that goes with it, the module has a 'patent pending Traction Control System'.
It costs $117 at Summit, or $AU164. sell for $70. I have cut a couple of the wires, you may need to lengthen them. I had this mounted under the dash to keep it cool. It will also mount inside a HEI dist in place of the factory module.