I don't recall it being adjustable. The one in the first picture was retained, but a good soaking of penetrant and it worked fine. The engine/transmission mounts are not slotted fore or aft, so there shouldn't be an issue there. Just making sure, is the rear of the body even with the rear cross member, or is it hanging over? There might be just enough play to allow you to shift the body forward, but not that much.