Is your set up standard Prevost or has it been modified?

My 8V92 1987 model had the gear box out in the open behind the rear doors and the exhaust from the turbo was well to the rear. Nothing was placed above the gear box. FWIW on early Prevost chassis the original fan had metal blades and was very heavy. A retrofit fan with nylon or fiberglass blades which was much lighter was offered to save wear and tear on the gear box.