I had a MTH RK 2-8-0 and bought another RK 2-8-0 boiler shell from a forumite to replace the original. The mounting holes were the same, but the casting was different. I had to dremel away bits and pieces to get the frame to fit inside.
I have a Legacy GP9, Wabash 484. When I got it I tried looking it up on the internet and the only thing I could find was an older, conventional model. I have an Atlas GP9 and while they both look the same dimensionally outside, I know they're not the same inside. Mounting locations and thickness of the plastic used are 2 things I can think of that would cause concern about swapping around any shells.
I'd take the chassis to a train show and try finding a shell to do a test fit with, unless you're capable/comfortable of making alterations. At the very least I'd get some idea of the outside dimensions of the shell to make sure it fits.
I'm in the process of making GP11 drawings, and along the way I've had to confirm the dimensions you're looking for. The GP9 cab is 10' wide, 6' 6" long and 9' 5 1/2" above the walkway at the top of the roof, while both hoods are 8' 10" above the walkway. The pilot-to-pilot distance is 52'. These are per railroad drawings.
From measurements I've taken (from photos, drawings and an actual GP9RM) the hood ends are about 26 1/4" from the pilot face (I've measured between 26" and 26 1/2" depending on the source) and the short hood is 8' 4" long. I haven't measured the long hood, but subtracting the short hood and cab length gives a long hood length of about 32' 9 1/2", and a total nose-to-nose length of 47' 7 1/2" (give or take 1/2").
Edit: I guess you were looking for model dimensions, not the prototype - which I don't have... In any case, at least you'll know whether a given shell is accurate!
Last edited by Michael E. November 11, 2013 4:33 PM
Rocky and mike, I am very interested in this thread. I have been gathering ideas and schematics and pics for building a B&M GP18. As I recall I had exchange some ideas with Diesel Dan. He did a wonderful kit bash of 2 GP18s. I have a body of a GP20 proto1. I also need to know about screw mount holes. All I need is a GP9 chassis. Does anyone know if the back motor has the speed tape and reader? To do it right I plan on dummying the front motor if I can. The nose is long on this type and the front motor will be in the way. Can you guys post some pics. Any will help! Love to see what you guys can do! Keep us posted.