H pipe vs X pipe vs no pipe

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http://www.forabodiesonly.com/mopar/showthread.php?t=57237
http://www.forabodiesonly.com/mopar/showthread.php?t=71131
http://www.forabodiesonly.com/mopar/showthread.php?t=86815
http://www.forabodiesonly.com/mopar/showthread.php?t=84458