cam timing

I spoke about retarding and advancing cams with a well known grinder one time who was also an avid drag racer,he said out of all the cams,cars,engines ect. hes only had one that actually liked being retarded beyond straight up and it was an unusual grind to begin with.From your post Im assuming your cam has a 109 lsa and is installed on a 105 intake centerline?.If this is correct I would say you could set it at 109/109-or "striaght up" which should move the power band up a couple hundred or so rpm but beyond that I would get a different grind if you still need more.