In a reply to another post asking about adding a VR supercharger, Hoosier Hurricane wrote that one of the parts that is different is the harmonic balancer. I did look it up in the Ford parts book and it does have a separate listing for the S/C engine described as Single Sheave 7-1/4" diam. damper-5 timing marks-4.84 long, Part# B7AZ- 312-B. I didn't find the original dampener from my father's Phase I engine and I didn't know there was a difference so I am using a single sheave #FOR2921 from Dampener Doctor. Anyone know why the supercharger balancer is different and will the one from dampener doctor work, the supercharger drive sheave looks to fit correctly.

Randy