Has anybody ran the Q2 on a stock header pipe or do you have to buy an aftermarket header. FMF has no specific information about this, they say you should not haveto adjust anything accept maybe jetting issues which are beyond their control. I bought the Q2 and have every intention on using the stock header. I use only stock jetting since I am only 321' above sea level, so I dont think jetting will be an issue. Any input would be great. 2000 yz426 is the bike,all stock.