They may have a different modulator on the tranny. One that pushes.
You can change that to a pull type fairly easily. Pull the cover off the modulator and look to see if it matches
the picture in the MC9 manual or the one I posted to KbunnyStar the other night.
If it is a push type you may also consider using the whole assembly off the fire truck and just hook your
existing pull-type throttle cable to it. that way you probably wont need to change anything.
That is the cable operated version on the MC9 for the 740 transmission and 700 series. ( stock )