Flip your gauge block around, you want the regulator against the smooth side, not the slotted side. Be sure you install the plastic spacer between the valve and gauge block. Remove the two o-rings on the smooth side of the gauge block to allow the reg to vent. Reverse those steps to revert to unregulated use.Plenum volume is minimal, so expect a good hit to your power levels.I haven't used the Lane regulator in the underlever, but have used the same regulator you are talking about in similar platforms. The Lane regulators work very well. It is perfect for backyard target shooting and hunting rabbits and squirrels if you are a good shot. His kit comes with great instructions, complete with pictures.If you are wanting power on the regulator, expect to have to do a lot of changes to your valve and gauge block to get there. It'll give you a good excuse to pick up a lathe