The angle iron piece at the bottom of the vertical track armor where the sheet metal floor bolts in, holds everything in alignment front to back. So start with them and the cross members and work up from there. Don't tighten any of the bolts up until you are at the horizontal track armor, as every thing has a little play, and it all needs to get lined up before you start tightening things up. If the track armor and side armor are already installed on the track you can come back and install the sheet metal floor later, but it is harder that way.
Steve
