if u angle the ecm right, ur battery box will fit flush. there is two dodads (some sort of plugs) attched to the battery locking strap, remove those and ur ecm will fit good. mine is about a quarter of an inch from its original place. i secured it with a single zip tie on the top for piece of mind. lol
Are ya'll attaching the ecm to the cover, or just letting it sit in there loosely? I believe this may be my next "mod"....