The one I am talking about was a fixed kit sort of like the upper cylinder lube kit for leaded gas cars using unleaded gas but sucks in water vapor/mist not lube.
i remember the water injection kits some used in high performance engines back in the day. was said to help keep engine clean and keep it from pinging as bad. never had the need for something like that because i drove the cowboy shit outta my old hot rod 72 SS Chevelle