what is the hole on the flange that wraps under the bottom of the front frame rail for. I was putting mine in place last night and thought it was for the bolt that goes thru the engine cross member on the bottom but it would not line up. I thought I would have to make it bigger but then when measuring the distance from the end of the front frame rail to the tower of the drivers side I realized the tower was to far forward. Then I thought well maybe it is for welding to the frame but I am not sure. Hopefully someone out there who has done this repair can steer me correctly. The old frame and tower was rotted out so badly I could not see how it was put together