I'm putting in an RV step tub directly behind my passenger-side rear wheel well, with the tub part projecting below the level of the steel floor by about nine inches (with insulation the steel box around it will be about eleven inches below the floor level). The spot where this box will be projecting below the floor is near where the rear shock is mounted (as shown in the first pic) so I want to make sure I have enough clearance there so that the shock can still be replaced if necessary.
I'm guessing that a couple of inches (maybe 3?) would be sufficient to allow the nuts to be taken off and the shock removed, but maybe there's some other aspect to this operation that requires more room?
Edit: that is not blood, by the way - red thread locker.