Modding one is a matter of taking it apart, plugging the solenoid hole with epoxy, removing the flow-control guts, and tapping the flow-control stem for your pilot valve. My valve's flow control stem was the perfect diameter for 3/8" NPT threads, so no drilling was necessary. I just tapped it out and screwed in a 3/8" ball valve.
UPDATE 8/14/2012: I re-uploaded the pictures and added some notes.
Also, if my memory serves, you have to keep the spring in there. It helps establish the seal until the valve is pressurized.


Thread this hollow stem with a 3/8" NPT tap.

Plug this with epoxy.

Remove these parts, you won't need them.



