I RUN 12" RACE BULLETS W/ A 3 1/2" SPIRAL INSERT SHOVED HALF WAY IN THEM AND SPOT WELDED. no racking , doesn`t sound tinney, no popping, no back pressure very free flowing. Can be done for under $50 .-----"full 3 1/2" exhaust dumped in front of the rear axle, w/ turn downs." Doesn`t stir up dust because of size. Not overly loud either !