I just got this bike and the guy I got it from said it has a dr.d header pipe and a fmf silencer. Im pretty sure its a dr.d header because I cant get the oil filter off without removing the header. Im thinking about switching it for a fmf mega bomb. Ive read the dr.d does the best tho. How does the fmf compare? Is it worth the headache to keep the dr.d?