[quickjack]

According to Inglese and Cam Techniques, 110 degrees is about optimal. Overlap needs to be minimal for low rpm good behavior. This would be less of an issue on a race only motor, as low rpm manners are not so important as top end power.
I would consult a cam grinder who has experience with Webers (Cam Techniques is a good one), as every engine combination and application will vary somewhat.