I can't say absolutely but I would think the engine was painted first then attached to the transmission. Tranny shouldn't have any paint on it.

OOps, re-read. I'm not an expert, nor do I play one on TV. It just seems that from what I have seen on auto plant assy, the engines were, built in one area, painted in another, and then sent to the assembly line and attached to the tranny. I'm certain I will be shown the error of my logic however