Happy day! I installed this C.S. Johnson stay extender ($18 from Defender, their part number 611925) and my problems with the new 150% genoa rubbing on the pulpit, especially when sailing downwind, are finally over. The extender has several adjustable holes on approx. 1" centers. As you can see by the holes, I used about 3" of extension. I took up most of the resulting slack in the forestay by cranking down the turnbuckle (hidden inside the CDI furler of course) and the remainder by tightening up my backstay a little. My mast is probably tilting back a tiny bit more than previously, but it's not noticeable. Bonus feature: easier to slip in the clevis pin at the bottom of the furler when rigging her up at the ramp - more room to see what's going on and line up the holes.
(http://i1108.photobucket.com/albums/h411/wnewman/StayExtender.jpg)