I finally got around to putting me 2nd battery in so here it is
Had to make a new air box and move it as far forward as possible
Had to bend the dip stick back, and fab the battery tray. It only just squeeses in.
You would think the battery where it is would get quite hot but it doesn't, it might be because there's a vent directly above it. The pick is with a 100ah but it will fit a 120ah