Not sure of all the differences, but i had a Firecore distributor and in the first week of owning it, i melted the rotor tip right off of the rotor. About the 2nd or 3rd blast on my new 511 at the time and the motor sure did let off a big kaboom as the tip bounced around in the cap, firing cylinders out of time. It was so violent that i thought i had ran over my alternator with a rear tire. I swear it lifted the rear of the car off the ground. Crazy. I never seen this before. I was also looking at getting one of Dons vac dist curved by him as well. Looks like a nice piece.