just make sure your running 35 degrees total and make sure advance is fully in by 2k rpm,,, if vacuum operated, plug carb port set total to 35 degrees full advance in by 2 k, tighten dist, recheck timing, reinstall vac hose and you should have 53 degrees,,,,,,, total plus spark, if not get hex head that fits vacuum pot and turn screw til 53 degrees is acheived, dont mess with total ,your just setting spark advance at this point, never set initial, only used to start on a rebuilt perormance engine. its always total, no wont affect starting 1 bit. good for a few 10ths or more. look at my other replies in other forums on tuning, hey why is that distributor in the back? heh hope this helps