I agree with Randy. Fill the stock voids.
No more twang or torque, but the piston hitting home still makes a sharp noise with a gas ram. Filling the void in the butt helps absorb some of the sound.
With the gas ram, you may find the gun prefers heavier pellets.
As far as any tuning, deburring and replacing the seal with a better one may be one thing you'll want to check on. My Whisper had a bad seal early on. Swapping to a gas ram made the seal worse, faster. Chaised my tail around wondering why the groups were getting worse until I replaced it. Now it's great.
You may find a cheek pad helps you get a good cheek weld so your eye stays aligned with a scope.
Get a good, strong one-piece scope mount and clean and locktite the screws, plus the rail.
With a compact scope and mount the guns is 7-1/2 pounds. You may want a sling if you ever use it for more than just yard pest control.
Good luck with it.
Paul.