When I got to my setup, the holes were already there. It was my dads project and he has since passed. So I am not sure if the holes were predrilled or if he drilled them. The holes were off somewhat. What I ended up doing was mounting the body to the floor pan with fiberglass. Once everything was lined up, front to back - side to side, the holes were even more off. So.. that being said, I wouldnt be too concerned about the line up of those holes at this point. Someone else might have a difference of opinion but given the direction of what I am doing, it makes more sense to me at this point.