The smaller of the two, I believe. I think the bigger one is noticeably more expensive. I bought a motor with this setup and was really happy with it so I keep buying the same one.Mike97760, Which exact NR Racing carb kit for the Predator 212 engine are you referring to? One that sells for $92.99, set up for Methanol with 21 mm carb bore, 15 deg Mount? Thanks! Mark