Maybe the Sports didn't come with the little baffle or whatever? I've noticed over the years that the Montero parts are slightly different than their Sport contemporaries even parts that look exactly the same. For example the Montero vs it's identical Sport steering wheel is slightly different internally and a lot of pieces on the Montero are more "finished" than on the sport. The trucks are built in the same plant but I maybe the Sport parts come from Thailand where the Triton is built?

1999 Montero SAS'd on Kings and stuff

1998 Montero trying to get a V8 Swapped