I would start with the jetting the carburetor had for the 283, it will be pretty darn close to what you need. The best addition to my truck I have is an air/fuel ratio gauge. It takes about five miles of driving to figure out how to jet your carburetor. https://www.speedhut.com/gauge/GL2-250/7/Standalone-Air-Fuel-Wideband-with-Analog-Out,-O2-gauge-8-5-18
