Fixed the problem. I put on the bigger pulley with the stock sized belt (fit no problem BTW), the car was still displaying the same symptoms. I was running out of ideas, so I started checking the plugs to see if they were fouling. The front ones looked fine. I started pulling off the back wires and the #6 wire came uncrimped as I pulled it off! The #2 wire as well.
These are nearly brand new ZZP racing wires, they have less than 2000 miles on them, and the first time I go to pull one off it breaks! Beware of these wires! I didn't twist and pull or anything, I just pulled straight out and the came uncrimped...
I replace all of them with a set Borg Warner wires and the car runs flawlessly now. I'll be getting in touch with ZZP tomorrow about compensation for their faulty product.