You need two IMHO. A blower doesn't blend as much as one would think. I run one system with two plates. Just remember to jet each plate accordingly. In other words if you want 150hp, then jet each plate at 75hp. Also remember that you get a lot more bang for your buck with nitrous on a blower because it is cooling that charge and increasing the efficiency of the blower. A 150 shot ends up being more like a 200+ shot.
Hi Dave, Welcome to the board!!!