One thing is for sure:
Because the Flyer articulateds have two-point articulation (where both engine sets pivot, like AHM/Rivarrossi used and Athearn uses in HO) overhang is less pronounced that a model locomotive that only has one-point articulation (like the prototype and high end Lionel and MTH O scale articulateds.)
I once owned a brass Sunset S Scale Challenger that could barely negotiate my 33" radius curves with one-point articulation. The boiler overhang was pretty severe.
Rusty
