are they any good on the 800,s 02 mxz.? ??? ???

Union Bay has a great reputation. I just had them port my 700 Summit and modify my head. Their own head looks sweet and I might go that way in the future. These guys do quality work and have the race results to prove it. However, I guess I can't really answer your question.

You might also consider RKT heads. They also have great reputation with the Mountain crowd.

i have a cudney racing head on on my 01 mxz 800 and it woke the sled right up!!!! :D . I :inlove: it it's awesome. give bill a shout.. www.cudneyracing.com.