The Race Demon RS carburetors have all the features of the standard Race Demon, plus these carburetors have removable sleeve venturi that are CNC machined from billet aluminum and color coded to indicate bore sizes. Changing carburetor size is easy. Simply remove the base plate, remove the old venture sleeves and install the new size. Switching to alcohol from gasoline. It's as simple as ordering a kit. With minor adjustments to the tune-up, this task can easily be accomplished with the simple hand tools on any racer's workbench.