I have been studying this for a few months now. Actually had another thread on the open forum but didnt have many replys. Dont bother buying those manuals on the net, waste of money. Get or make a generator that uses pvc and 304 stainless plates NOT bolts, wire, mason jars, ect. On ebay there is some pretty good ones forsale. On a 96 or newer vehicle you will need a map sensor controler and 1 or 2 o2 sensor extenders. On my 2.3 liter Ford Ranger I was getting 25mpg but and now getting 37 so I'm pretty happy with the results. Very limited gains are found on big v8's though from what I've seen. Get/make a generator that will produce at least 1 liter of HHO per minute.
Remove all the warning label and let nature take its course