After trying every other suggestion I could find to reduce the head buffeting, I finally decided to try tilting the windshield. I didn't think it could make much difference. Boy was I suprised!
Tilting the windshield as shown here did the trick. Lowers helped a little, larger windshield not at all. I am 6' 4" with 34" inseam. The buffeting is now solved and I like my larger lowers and windshield but before I tilted the windshield I still have enough buffeting to cause headaches. Now when I were ear plugs and a full face helmet on the freeway (speed limit here is 75 mph) I feel just great.
One modification I made was instead of drilling holes for new bolts I just catch the edge of the bracket on the existing bolt (I need to show a photo).