I have a few questions I hope some of you can help me out. Question#1. I am currently in the middle of converting my 99 YZ400 to a 426 internals. What parts do I need. I have been told that all I need is a 426 rod, wrist pin, and piston and cylinder. I was looking through catalogs and their are different part numbers for head gasket and base gaskets for the 400 and 426 If they interchange why are the part numbers different. Question#2 I started porting the head and was trying to figure out how smooth to make it. So far I have just smoothed out the casting marks with a 120 grit sandpaper roll on a die grinder. Several people have told me to leave it a little rough, and some people tell me to polish it as smooth as I can get it. Who do I listen to. Question#3 What kind of cam should I use. I have been told that Hot cams are junk. I installed a set of hot cams in a buddy of mines KFX400 quad and the installation went smooth and he was happy with the power increase. If they are junk what other cam options do I have. There the only manufacture that I have found that makes a set of cams for my bike. If any body has any input I would greatly appreciate it.