So... I bought this 05 RMZ450 last year from a buddy and he had apparently had a Hotcam exhaust installed in it. I'm not sure how it happened, but on my last ride of the season my exhaust cam cap came loose and took out the head. I haven't dug any further to see if there is anything else wrong, but I would not have known anything was wrong had it not been for oil coming out of the valve cover - initially I thought the valve cover gasket went, but after getting the tank off and seeing the valve cover bolt protruding a bit, I had a bad feeling that it was something more. But I'll say this, it got me back to camp and never missed a beat. So, I was doing a search on a head swap to see what the compatibility was on these and found the below quote... Put the cams in and install-05,06,07 will interchange. The 07 takes alittle more work. (Original thread: http://www.thumpertalk.com/forum/showthread.php?t=947839) Can anyone elaborate on this? How much more work does it take for the 07 head? Is there a benefit to convering to an 07 head that I won't get from using an 06 head? I also plan to have the cylinder replated while I have his apart and will inspect the piston and bottom end while I'm at it. Can I get away with just a replate and rings if the piston is still in spec or should I replace that as well? Any comments on the Athena 490 big bore kit? Where is the best place to get an OEM head cheap? I'm seeing prices around $600 for one but noticed that member "Faded" got one for $423 as listed in his rebuild thread on another site: http://www.allthingsmoto.com/forums/f-23/2005-suzuki-rm-z450-build-49775/ And, as a final question to anybody that has done a top end on an 05 RMZ450, is there anything else I need to know before breaking it down further?