What your looking for is the engine spec - while i have it myself i cant find where to download it so heres an easy fix
http://www.auran.com/TRS2004/DLS_downloadasset.php?DownloadID=74026
Find the locomotive in CMP, then open for edit > edit in explorer.
Find Config.txt and put kuid:
9000:51040 in the place of kuid:9000:51049
Then commit
(And all because a mr Dietrich ryan thought it was a good idea to put a sw1500 enginespec on a gp38-2)
William