I have a new Predator 6.5 with the aftermarket air filter and adapter and plan to re-jet the carb, add header with briggs type screw on muffler, and want to advance the timing. I would like some input on how many degrees I should advance the timing and maybe the size jets I should use in the carb? My Cheeftah 1300 is just a neighborhood hotrod, not a racer but I do want it to haul a$$. Any info is greatly appreciated.