putting williams GP-7 shell on MTH railking chassie.

If it's an older Williams GP7, not WBB, it mounted to the frame with a single screw on each end through the nose into a metal tab on the frame.  I believe MTH engines have one screw hole through the bottom of the frame in each corner and the screw threads into bolsters in the shell.  Not an easy swap but possible with some work.  There have been threads about how to repair broken bolsters here on the Forum so you may be able to construct bolsters inside the Williams shell or you may be able to rig something on the frame of the MTH to accept the mounting screw through the ends of the Williams shell.

Thanks very much. I think I can handle the changes you mentioned. I have yet to buy the MTH Geep so my only worry now is are the shells the same size?

I've got a number of MTH and WBB GP9's.  The screw hole issue aside; I am almost certain the WBB shells are a bit smaller than the MTH.  If you can hold off a day or two; I'll do a test fit myself and let you know if it works.

Unless you can find a larger MTH FA model; swapping shells with WBB won't work.  The scale WBB FA's are a lot bigger than the current PS3 MTH FA's.  Even if you're talking one of the WBB FA's that is based on Lionel postwar Alco FA's; the shell is still larger than the new MTH FA's.  In either case with the FA's; I believe the WBB shell would overhang the MTH frame.

Curt

Looking at online diagrams of MTH GP-9 it looks like the body is integrated with the running boards which Williams is not, therefore there may be more cutting than I would be prepared to do.  Looking at diagrams of Lionel geeps with tmcc  the frame/ body looks like a better match. Atlas geep would work would work also but I would think that an Atlas geep would be much bigger than the others. (does anyone Know)? 

I just tried the test fit and it won’t work.

As you note above; the MTH shell incorporates the running boards and hand rails whereas WBB incorporates those on the frame.  Additionally; the WBB shell is a bit narrower and cannot be pushed past the smoke and volume pots attached to the MTH frame.  

I’ve included a few photos as reference.

Curt

Thanks for doing all that work. I guess my only hope is to find a dcc MTH Red white and Black GP-9. They appear to be rare.