The main thing that needs to be level is the left to right tilt of the engine, theres a pretty good amount of adjustment by tweaking the engine on the mounts to adjust it.
Yeah, mainly left to right is what I was wondering about, and also wondering if there was any front to back shimming that needed to be done (similar to left/right tilt). It makes sense to me that left to right will be my primary concern. Thanks for the help everyone!