While it is in the planning stage,and you have removed all the stringers and bearers etc. You have to workout which way you would like to install the diagonal twist. Dont level it before putting bearers & floor back in that way it can pull hard to the left or hard to the right whichever way you prefer and you can struggle to keep it straight. I know this because I used to build boats and have seen it happen from new and also after repairs. Makes them a better challenge to drive and something to look forward to.
Hope this helps.
Mick