Yes, stock carbs. I changed everything, but finally settled on just one step up on the main jet, 130 to 132.5, and a 1/3 step richer on the needle jet. The needle jet is another story of my micro tinkering. Also, you may already know that the 72 crank won't work with the kit, so I bought a whole 75 bike with 12K miles and used that crank. I also used the 75 cam. A 75 cam is a bit milder than the 72, but I didn't care for 2 reasons. I had to use a 74 or newer cam for the cam sprocket and I didn't build it for all out balls, I built it for reliability and longevity. Plus, my 72 cam was really worn. So far, at about 14K on the kit, all is still good.