I have made a few morphs with truespace using Compose as the middle man. What you do is import the part into compose as an object and export it to .cob I prefer to use compose to scale it first using a uniform scale setting of 1.0. Using Truespace load the object but don't move or scale it , I don't know about changing the axis though I wouldn't recomend it. make your morph and save in the .cob format with the ascii box checked. Load it into Compose and un-scale it if you changed the scale , if you used 1.0 to scale use 0.1 to undo it, then just save it as an object and it should work. I think Compose is available in the freestuff section here.