My 02 valves lasted a whole season (1400 miles) with regular inspections, but the clearance on one intake closed up rapidly at the end. The 03, valves, head and springs all have the same part numbers, so you guys might want to read up too? I had several long discussion with Kibblewhite, the only makers of Stainless steel valve kits so far. Without getting technical, They said all titanium valves are kind of soft, and the honda valve seats are kind of hard, while the springs are borderline too soft. This unhappy combination means the valves can sometimes bounce on the hard seats which accelerates wear. I found two other companies that can supply SS valves (custom) at very reasonable prices, but neither of them knew about CRF's and had the appropriate spring kits. For now Kibblewhite http://www.blackdiamondvalves.com/Default.htm is the only show in town. They are now selling only through distributors, the largest of which is web cam I think. They offer "white Diamond" valves with hard chrome stems right now, but will soon be shipping the "black Diamond" versions with some kind of hard black surface treatment. They only sell the full spring kit for 4 valves, and say the exhaust springs are slightly stiffer as well. You can however only use the SS intakes with your stock exhaust, but you might as well use their SS exhaust too while your in there. I got prices of $32.00 per valve, and $185.00 for the full spring kit. All reports so far indicate that this completely solves the valve issues. You do need to cut the valve seats before installing valves, and you can buy the neccesary carbide hand cutters from Neway Mfg. for a little under $200, or trust some shop to do it for you. These hand operated cutters are better than grinding stones, and are what 90% of all dealerships will use. I don't know what the going rate is for valve seat cutting, but I chose to buy the cutters. I am a Honda meechanic from way back, and won't let anyone touch my motors. I ALWAYS freshen up the motor before each season no matter what I ride so none of this bothers me too much, but the cost was a bit high. The whole job with valves, springs, piston & rings, gaskets and the cutters cost me around $650.00 I'll forget all about it when I hit the trails this spring, and hopefully it will increase the resale value??