My intake valves on my 01 426 will not hold a clearance. I adjusted them 7hours ago and the clearances were in spec .10-.15mm. Now after just one day they are out of spec. .07mm, .05mm, .10mm. The exhausts are totally fine and still holding from their last shim adjustment nearly 120hrs ago. So, I believe it's time to do a valve job. I don't want to just buy a new head, because of cost and I have some porting done to my existing head. I figure I will just have the seats re-worked and install new valves, springs, and all the other clips and retainers. What are some good aftermarket SS valves to use? Stocks OEM valves are expensive and maybe not the best route to go since I won't be racing this bike anymore.