IS UM aliminum airbox with 250R filter worth it

[rgorm2500]

i was wondering if anyone has the the UM alminum airbox with the 250R oversize filter, is it worth the money. Is there a real noticeable difference in power. How much do they go for. I would like to know before i go and try to buy this setup.:)

[quad97]

I would put on a 400ex intake boot w/o airbox lid first. The stock intake boot is a bigger restriction than your air box. If you want more flow than that, put some vents in the sides of the box. Twin-air makes some good ones, really helped out on my ktm, just make sure you safty wire them in.