Do I need a regulator for my FX Royale 500?

Funny you should mention that today. I've finally decided to send mine off Monday to AOA. Mine is currently getting 40 shots at 2% ES and 28 shots at 1% ES at 902 fps and 904 fps averages (shooting Kings). My 500 does not have the power adjuster wheel either. I'm hoping for 65-70 1% and under ES after its regulated. I'm going to try and stay at least 900fps with the regulator installed. Talked to Kevin at AOA yesterday. The cost including return shipping is $210. They can send a shipping label by email to you for $35 also. I'm sending just the action/barrel and shroud so the shipping should be less than $35 one way. It'll be nice just to filler up and shoot and not have to worry about the bell curve.
Jimmy