I believe in 04 they went from the 7E down to the hotter 6E and I am guessing that your running the recommended 91/92 octane as recommended by your OM. Not going to dredge up the OCTANE discussion again, there is enough for you search on to read about that. Reading your plugs is the final tell tale. If it were me, stick with the 6E as that was what was later recommended (much like they reduced the size of your oil cooler) and I would think your alright. If you get pinging on high octane, bumpt it up to the 7E but I dont think you will. My 04 I run the 6E, 89Octane and have a K&N big sucker air filter. My plugs are finally burning righ and my exhaust is no longer sooty with that raw gas smell at a light..
My 2 cents... Safe ridin!
2011 White Vision - Nuvi 550, Lowers, Lloydz 2nd filter, Vic perf filter, CB/Icom, 96 Brake LED's, Clear Signal lens/Switchbacks, VIC Hwy Pegs, Stebel Horn, 7Jurock 15" Shield, PCV, Lloyd ATS and Variable intake, Ness honkers
2004 V92 TC - S1 flash, level 1 slip-on, Ness big sucker K&N, ISO Grips, 4x1.5 Highway Hawg Risers, extra chrome (never too much), JM 2k CB 4' antena, Mustang seat, HD Front TS & Lowers, OD Pulley
Retired Navy SCPO