Had an intake valve going bad on an '02. Upon removal the valve itself was clearly wearing and the seat was not worn. Replaced both intakes and of note was that the intakes clearly have less spring tension than the exhaust valves. Maybe the new springs (on the intakes) were more resilient but I've seen references to the installed spring length being suspect in the valve wear issue. In any event, all I did was drop in new valves and springs and the clearance came out a perfect .006" each side.