I have the brison 3.2 and I know Gary Allison the owner, He feels that he gets more horsepower from the standard Ign that he supplies over the sync. spark. He can run less inital timing to help the engine start, more total timing for better top end and the advance comes in slower making for better throttle response. In my own experiance I have found that small changes really help performance with differant props and altitudes. If you do run sync. spark I would like to hear your findings.