Using the stock housing, you will need to use teflon tape on the back screw that you used to adjust the velocity. You will need to tap the vent hole on the side of the cylinder for a setscrew as well.
I would add some spacers to shorten up the trigger pull a tad bit. A Delrin bolt used to be a must, but I haven't seen any of those F/S.
Empire - Empire BT - JT Paintball - JT SplatMaster - Spyder
If you get confused just listen to the music play.