Please try the 400 gasket, I've asked that question without getting replies, and around here, there seems to be a huge price discrepancy between model years on the parts fiche so it would be a good thing to know. Hey Matt16, here’s the scoop on the valve cover gasket. The 99 and 07 valve covers are very close, but we all know that close only counts in horseshoes, hand grenades, and slow dancing, but is perfectly acceptable when the nearest properly fitting part is 2000 miles away. Although the 99 gasket zigs in some places where the 07 cover zags, lengthwise it is nearly perfect, about 2mm longer than it should be. I heated mine up in warm water, and worked into the slightly different channel in the 07 cover. The extra length showed up along the straight side with the 2 half moons, there was a hump in the gasket. I squirmed it around until it flattened out, like when you accidentally remove a big rubber O-ring from a machined groove and it instantly seems to grow an inch and you have to stuff it back in. I glued it in place, little by little, with 3 bond liquid gasket, let it dry under a bit of pressure, and it held perfectly. The center piece at the sparkplug hole is also different, but I re-used my 07 piece. I had to cut the round piece from the 99 gasket. While this does seem to work, I wouldn’t recommend buying a 99 gasket and going through all this just to save a few bucks. Now I have a question – is it physically possible to install the valve cover without removing the engine??? I spent an hour trying to replace the cover and can not get that darn thing in. I removed the top mount, radiator, water pipe on the front of the head (AIS is already gone) and block heater but no deal. The wiring harness seemed to be interfering. It was -30, so the harness was like a piece of steel and I had to steam it to get it to bend. That still didn’t work so I removed the front number plate, unplugged all the plugs from the harness (and had to steam all the plugs to get them apart and steam the wires to get them to bend) and pulled the wiring harness completely out of the frame above the head, and I still didn’t have enough clearance to get the cover in. I was getting hungry so I gave up and came in for supper. Tomorrow I’m going to remove the clutch and throttle cables, unless someone can give me the proper contortion sequence. Maybe the aluminum frame shrunk in the cold, maybe the 99 gasket is an RCH thicker than the 07 and is interfering. If nothing else works I’m pulling the motor mounts 'cause I'm definitely riding on the weekend. It’s supposed to be beautiful and sunny tomorrow, and a full on heat wave on Sunday - I’ll finally be able to wear those MX shorts I got for my birthday!