Heres a question for ya, on one if my duallies @ WOT the fuel pressure guage reads between 5-7 .At idle its @ 15. I dont think it should go that low. I have a FASS 95 electric fuel pump on it with 110 injectors. Im thinking maybe the 110 injectors are sucking so much fuel the FASS cant keep up? Any thoughts?

http://www.thoroughbreddiesel.com/airdog/2.htm That AirDog II has the adjustable fuel pressure and flow demand upgrades but costs about $100 more. To be honest, I have never had to touch the fuel pressure adjustment on my AirDog I. For a short time the fuel pressure was staying around 22 psi because my fuel return valve stuck shut but eventually did open and now my fuel pressure stay rock solid at 18 psi. For the most part, you really won't have a need to adjust fuel pressure once everything is set up correctly. If by chance you do need to adjust fuel pressure, it can be done by changing shim washers. If you go with the AirDog I, I would get the AirDog 150. If you go with the AirDog II, I would get the AirDog II165. You can do fine with the AirDog 100 but the AirDog 150 is the same price and leaves room for future mods. It is a coin flip. I guess if I was buying an AirDog now, I would go with the AirDog II 165. I purchased my AirDog from Extreme Diesel: http://www.xtremediesel.com/fuelsystem_1.aspx?page=2 Hope the video's and links help. I am sure others will jump in with their comments and observations too. I am sure you will be happy with either. Good luck!