no you don't haft to it will go right on the blaster, crappter and Almighty shee you will haft to use the spacers that came with it so there is no play between the sprocket and carior and rotor carior bent my first g force and spun the splines out of the g force hubs just put new ones back on over the weekend and didn't put in washers had to much play lost chain about 7 times didn't brake anything thank god but i have billet carior tho might not need washers with stock carior