In the photos i've seen the only part of the exhaust pipe that's visible is from the rear. Sometimes in modeling we have to make compromises and eliminating an almost never seen piece of underbody detail in favor of a simplified reliable power unit is common sense to me. Those HO power units will NOT work. If i can find the one with NWSL gears, etc. in my junk box i''l sell it to you for $10 so you can see for yourself!