and my research shows me that a staight pipe system (headders and straight muffler like a glasspack) is best for high rpm hp in the 5000 plus rpm range, but poor for power under 4000rpm because we have no back preasure on exhaust. but x pipe gives a little backpreasure at lower rpm like 3000rpm and less, but our 6's arent going to see 5000rpm often, which is why x pipes are great for our low rpm/non race motors
