What I do if I'm wondering about that is go to the manufacturer's website and look up the engine's exploded diagram that gives the part number. Than you can check the other engines and see which one uses the same part number.
Very old Atlas HO engines used a metal frame as PC101 noted above, in more recent years the frame is plastic and fits over a metal chassis. So the same model engine from different types may be different in that respect.
Thanks for the info.
I do not see the HO scale Atlas RS1,2 or 3 body/shell drop fitting down on to the Atlas GP7 chassie/frame happening.
Atlas RS1 PC #9915, has metal walkways (frame and walkways are one piece).
Atlas RS3 WM #186, has plastic walkways (frame is seperate from plastic walkways).
Atlas GP7 RDG #608, has metal walkways (frame and walkways are one piece).
All three together showing the different fuel tanks.
Left click on the pictures will open it to a larger picture that can then be zoomed in on.
Will an Atlas RS 1,2 or 3 shell fit on an Atles GP 7 chassie? If so, where is the best place to look for shells? Is there a site that shows what shells can be swapped with different manufacturers?
Thanks,
Fred