[timschot]

Keep in mind, with super high pressure, you can pretty easily pop the return line off the nipple at the tank. Happened to me twice before I did the drill mod. Hasn't happened since. I was reluctant to just put a tighter clamp on, because I'd rather have it pop off there than in the engine bay.

I would do what Scheides said.. put a fuel pressure gauge on there (or have Ron do it) and if it's crazy high, do the drill mod and see if it helps much. It will definitely help, but it might not be enough with the w400's flow at idle.