My used 04 YZ 450F came with a Pro Circuit T-4 + head pipe installed and is pretty danged loud, giving me a headache after an hour on the bike. Without going to the trouble of re-installing the stock silencer and headpipe for a field test, how much dB quieter is the stocker at full throttle? The T-4 sounds cool for a while, then makes my head feel like this when I am on the gas: If the stocker is 5 dB less at 3/4 throttle, then I will probably put it back on. I would have done a search, but searching is down right now. So, does anyone remember how much quieter the stocker is? The sound data chart from the government website is confusing.