My motor only had 29,000 miles on it but since I was putting in a Wisco 1075 kit I thought I would do it right and get the heads redone also. I called around and found a place in Dayton, Ohio that seemed like they knew what they were doing. I had them do the seats and the valves and clean up the ports. They also took a light cut off the surface off the head to make sure it was straight. When I got it back I never checked the valve stem height (BIG MISTAKE) but just anxiously put it all back together with my new Wisco pistons. Well, when I went to adjust my valve clearance I found I didn't have any even with the smallest shim
. After much screwing around I managed to save the head by buying new valves and grinding stems and valve keepers. I guess what I'm trying to say is make sure the shop knows what they are doing. It probably wouldn't hurt to discuss it with them and copy the pages out of the manual that shows the valve stem height measurements. You're right in that you only have one shot at getting a good valve job or a piece of scrap. Also, when you talk to the shop ask if they have a Serdi valve grinder as that machine makes all 3 cuts at once and is supposed to be the best for this head. Just my 2 cents, good luck.