Cost, performance, etc., as mentioned. You can go with an aftermarket 'turbo' muffler and get lower restriction without adding much noise at all. That's what I did. I also had the exhaust relocated for clearance.
[Linked Image]
[Linked Image]

HTH,

Jay

1991 Trooper - DEAD! 2.8 V6, 5 spd, 4WD, HD clutch, 2.25" exhaust, EPROM Chip, KC/Hella, Aisin hubs, Rancho 9000X's, Panasonic/Infinity/Alpine
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