Hey CA ExhaustCoatings thanks for posting this link awhile back.
http://daughertymotorsports.com/howto/tankvalve/tankvalve.htmlI'm going to try doing the same to my 98 Tourer. I have a cover set on the way from HDL so if I have any problems replacement parts are in the mail. I've been shutting off the petcocks for many years it won't be a problem.
Mine is leaking down the vacuum line and fouling the plug in the #6 cylinder. So the vacuum stuff is going.
I'll let you guys know how it goes.