>The output of the pup is really high
Contrary to what many board members seems to belive: Yes, it is. :) All L-500's are powerful devices - compared to most other passive humbuckers.
The L-500R is a really great bridge pickup, and combined with an L-500C neck pickup, your LP will have a top end response no stock LP will deliver.
These pickups will do very well with a Q-filter. If so, I'd seriously consider master volume and tone controls.
Then you'll have to move hot out wires from the pickups to the 3-way switch outer lugs and then run a wire from the center lugs of the switch to one of the volume pots. You can leave the tone pot wired to this volume control as it is. The two remaining pots can be used for Q-filter control and coil cuts.
Coil cuts will introduce hum, but if you don't mind it, it will do no harm;)
When coil tapping, position the bridge pickup so the coil closest to the neck will sound. Then you'll have a bit more output and better bass response.