what would be the best complete exhaust system for a 400ex with a:
-dyno jet kit
-fuel filter
-parking block off plate
-ehs racing open airbox cover
-magnum rev box
i was looking and i thought the lrd pro 4 exhaust was probably the best, what about the big gun evo limited series exhaust, hmf ballance exhaust

 

big gun evo limited series exhaust

 

Yoshimura RS3. Pricey but worth every single penny.

 

i just have the slip on version of the lrd and i'm quite happy w/ it.

sounds and looks good.

w/ any exhaust change you may have to rejet again.

especially since you are already running an open airbox according to your post.

and what to you do w/ the bike.... trails... track....? if your not racing it you'll probably be just as happy w/ a good slip on
rather than the full exhaust.