Hey Frank, I remember reading that the minvan 3.0's went from a 2.25" exhaust manifold outlet to a 2.5" outlet for some increased power...maybe the Monty's did the same?
From Allpar, under History


-Todd
1987 Montero 2.6l 5-speed (Sold...but I still miss her)
2008 Jeep Patriot Sport 4x4