I purchased an aluminum underdrive supercharger pulley from Bluetooth racing as an alternative to Pulley Boys because of availability issues for my Series 1 L-67.
I have used this pulley through 1 oil change ( 2500 miles ) and have noticed a few things.

1. It slighty shreds the backside of the belt.
2. The rib grooves are too sharp and cut into the belt a little.
3. The pulley is not as small as it should be. Folks with smaller pulley boys pulley'* are getting about 1 to 2 more PSI of boost than I am.

Overall it'* a decent piece but could be better. I recommended it on this board in the past.
I still recommend it, as this part is hard to find ! Just be aware it'* not perfect.

JLathem

If you have problems, you can always try to get one from ZZP. They have S1 pulleys while supplies last.

Hmm, the pulley I got from ESM (I believe to be Blue Tooth'* supplier) didn't have those problems.

You know what the problem is? You should've ordered an overdrive pulley.

If it'* shredding the belt edge closer to the nosedrive, make sure it'* all the way on the shaft.

I was thinking the same thing.