I was checking out Bikemans website tonight and found a head for the 600HO. I'm thinking its made by SLP, but i couldn't find any info on the SLP website. I've been also looking at RKT's head. Anyways, I was just wondering if anyone has any experience with running a different head on the 600's and what kind of gains can be expected. I'm looking for something to increase my performance, but I don't want to spend too much. I'd really like to go with a 734, but its not in the cards this year, hopefully next. Anyone know any good improvements that are relatively inexpensive??