Ported and polished cylinders, knife-edged reed blocks, installed 1/2-inch reed spacers, boost bottle and Pro-Flow K&N setup. Kept stock 28mm mikunis, but switched to carb caps from earlier model RD400s, because the Daytona single-cable carb mechanism made changing jets a PITA.
Hard to see in this shot, but I fabricated a simple "dash" for the fairing from scrap plastic (kids' taboggan?) to cover the headlight and wiring, etc. A couple of generic plastic caps from the local Ace Hardware filled the holes for the handlebar mounts like they were designed for it. Neat and clean.