Cdi Box Worthwile On My Bike?

[THE 400EX DUNER]

ANYBODY WITH SIMILAR MODS: WILL AN AFTERMARKET CDI IGNITION ADVANCE CURVE ACTUALLY HELP ME ANY? FOUND SOME AS LOW AS 40$ ON EBAY BUT ARE THEY CRAP LIKE THE WHITE BROTHERS BOXES ARE? LOOKING FOR CHEAP POWER. ALREADY DONE THE CHOKE AND HEADPIPE "FREE" MODS. ANY OTHER NEW IDEAS OUT THERE? SEE POWER MODS BELOW.

[krt400ex]

if u r not constantly banging orff the rev limiter, then a cdi box is of no use. what is the free headpipe mod?? and did it help??

[THE 400EX DUNER]

the free headpipe mod is to take the headpipe off and grind the flange welds down flush inside the pipes, which supposedly impeade air flow from the exhaust ports a little bit. dont know if it helped as i had it off for the cam and piston swap anyway, but you cant beat the price.