Not me, but a friend who didn't want to spend the bucks and slapped a 70's Duraspark into his carb'd roller 5.0. It ran well for a couple weeks then started missing and quit completely in the middle of an intersection. The gear teeth were razor thin and a few broke right off and stopped it from spinning. The oil was full of filings, bearings and cylinder walls were ruined. Cam itself wasn't harmed.