use a 4 GM HEI modual instead of the Duraspark box, the DS box is about $80 for a good 1, and there known for going thermal. www.fordsix.com has info on how to do this.just get an old computer CPU heatsink and ziptie the modual to the heatsink with thermal grease on the backside, if you want it plug and play, hack the end off of an MSD 8869 connector, and wire it to the modual, that will give you a duraspark end