Good catch, Jerome. I've heard about the 3623, which was, I believe, the BN 330. The story is that BN had some SW-1200's with flexicoil trucks that they traded in for SW-1000's. The 330 was involved in a wreck and needed truck replacements and a pair of flexicoils were taken off one of the SW-1200's. I have no idea if that story is true but the 330 did not come with flexicoils so they came from another engine. One thing it proves for sure is that flexicoil and standard AAR switcher trucks could be swapped on the same engine with no problem.
