Skip forward a bit. The frame rails are straight and smooth, and the crossmember is here ready to install. This is just how you receive it from Scott's. It is one piece and ready to install. There will naturally be a little bit of final trim fit, but it's basically ready to go.
A little grinding and it’s a tight fit and ready to line up.
So where does the crossmember go? That’s easy….dead center of the wheel centerline.
A quick tack, and booyah, it’s in.
Somewhere is a really cool picture with a level on the crossmember to show how to level it……but instead I’ll explain.
In short, you want to install the crossmember level to the ground with the truck sitting at ride level. Look at that sentence carefully. The truck is at ride level, not necessarily ride height. If you want a 2” rake in the truck, then level the truck with a 2” rake, and install the crossmember level to the ground. If you want the truck straight level, then level the truck, and level the crossmember to the ground.