Are the cog pullies from Paxton and Vortech interchangeable? I just bought a Novi 2000 and it is set up for 16lbs, which is a little much till I build a better shortblock. I'd like to run 10-12lbs with it. Can I get cogs the right size to make the boost I want?, or will I have to go to a 10 rib set up? Thanks.