Robin,
Nice to have you on the forum.
The text editors on this site sometimes give trouble. Something happened to the first 3 paragraphs telling us what engine and track you are talking about, plus perhaps quite a bit more to set the scene.

Modifications like that are going to destroy the scale appearance so you can make whatever changes are needed to make it work. If non bogie it would depend on what minimum radius your track is plus what back-to-back flange reduction you could still get through the points with. If six wheeled use a flangeless centre pair. Either way you're going to get inclreased flange wear. Could be a bit of a problem then moving to another track with less check rail clearance.
Better to go straight for a bogie design and tell the rivet counters the loco was running an emergency configuration after the engine shed fire of xxxx. They will have to go away and look that up.

On raised track you want to get low so better to have a truck behind, a pad on the tender to rest one arm on and you probably still need extensions on the controls.

Edited By Bazyle on 07/10/2013 12:34:05