Our class has HP/Tq limits. The chevy boys have to restrict their motors to 267/317 max, and that's with weight penalties. 260/310 is where you want to be so you don't have to take penalties. The Fox chassis is allowed 3100lbs, SN is 3150, 3rd gen is 3150, and 4th gen/S197 is 3200. That's with driver when you get off track.