If you are trying to break the motor in, which it sounds like you are. You are doing almost everything wrong. You maybe getting bad #'s on principle alone. A 22x8 brambula is a rather large hunk of wood similar to a Menz S, which should not be used until after break in. Break in will start in another 50 or so gallons if you are using synthetic oil from the get go.
From the information you have given, it sounds like exhaust restriction, second something is horribly wrong w/fuel/intake/porting/timing. Or operator error.
Try running you engine with out the S&W's on. You should see a huge increase in your numbers.
Kurt