With the head off, i just leave the springs out and bolt one cam in. Put a shim in the first bucket to be clearanced and slide the valve in to its seat. check clearance and go from there. If you have a 200 shim in and no clearance yet, gring the valve stem by inserting it into a hole you drill through a board and clamp to a bench grinder. Take off a little metal and recheck. If you have to take more metal a second time, slide a retainer onto the valve and insert the keepers, look at it to make sure the stem is still above the retainer, if it is you have a green light to take off more material. Its easy to take .002 at a time off the stem. drill a nice tight hole in the board and oil the hole, c clamp it perpendicular to the grinder wheel.
