By the way these can really be helpful in terms of extending your engine life/performance. Not just a wasted costly add-on. Or for my particular application. Having read quite a few specs on this engine it is probably a good idea to have one. They can cost anywhere from $10.00 for one that is homemade to $80.00-$300.00 average for one designed for the Crossfire. There is quite a lot of info on these if you do a web search. As you can see from Mister Taz it can be installed at home.