A V-8 with dual exhausts and a straight 6 with 1-2-3 and 4-5-6 connected duals are two entirely different animals. The six is very even in it's firing. The V-8 (unless you have a 180 crank) is not. By adding a cross over pipe to the V-8 you allow the firing order to fill in and become smooth. You can see this on the V-8 by looking at the distributor cap and noting the firing order, 1 5 4 2 6 3 7 8 with 1-2-3-4 being on one side and 5-6-7-8 on the other. Our sixes make more power when a good system goes into a single pipe, like JD's a couple of posts back but we like the sound of split pipes a lot better for the street.
