We run our rear pretty much center in the car, the front wheels can be adjusted in our out with your arm lenths to match. Now and then we might shift the rear, but have never really seen a gain. Depending how far back you are with the rear, due to the curved frame rails there is not a whole lot of side to side movement allowed with the 6" rule. Note: be careful to check both sides for the 6" rule, I know of a guy was DQ'd cause neither side was 6" (bent frame I would think).