Hi all, this is my first post here. I'll probably have a million questions coming up. I had a 2000 400EX given to me that had the 440 kit put on it a good while ago. This quad needs some work but nothing major. I know I need a new top end for it for sure. I was thinking about getting a new cylinder jug and piston and all that stuff, new head, new valve cover, and a new cam. The valve cover is off the bike right now and I know it needs to be replaced as well as the cam. When I pull the head off this weekend, I'll be able to tell if it's good or not. My question is: if when I take the head off and it's ok, would it be possible for me to run the 440 kit with a new stock head? It seems possible to me, but I'm new to rebuilding 4 strokes. Thanks in advance. O and btw, the whole idea of not just replacing everything is that I'm trying to do this as cheap as possible, but still have a dependable quad.