So I'm at my shop this morning digging through my shelves for a part....and I find a custom ATI Harmonic damper I had built for the race car. Here's the thing, it has a 6.8" 6 rib pulley on it.
If you run into issues with belt slip on the SC.....give me a shout. Changing to a larger crank pulley will allow you to run a larger SC pulley which will help with belt slip. I've also got the drive mandrel for a dry sump pump that mates to the ATI damper as well....