I recheck and readjust the valve lash every time I remove and replace the rocker assembly.

My plan it to clean up the original cylinder head and put it back on, then select one of my three other cylinder heads for a proper rebuild.

Everything I've read about cylinder head work suggests that a good shop is needed. What's the best way to determine is a machine shop can do a good job at a good price? What has been the going rate for a valve job - assuming that I've bought the valves and guides myself?

I've been mulling over getting the head flycut to take the IPD double-wound springs. Is it worth it? Would that interfere with the machining to put in the B20-style valve stem seals?

Are there some smaller-machining jobs that I could/should have done just to demonstrate that the shop is competent before letting them at one's expensive valve components?