For my Cosworth head rebuild I measured all the valves (just a couple of tenths wear on the inlets, about five tenths on the exhausts) and selected sixteen guides from a big stock to achieve my target clearance range. Bob, the machinist, said the guides would need to to be reamed, but I wanted to trial fit the valves, first. I had already meaured and trial fit the loose guides to the valves and the fit was perfect.

Once installed in the head the valves didn't fit.
It appears that when everything cools down the interference fit creates a few tenths distortion here and a few there - enough to create some minor interference. One pass with a 9/32" reamer and the valves fit perfect!

The guide clearance spec you listed of 00-.01 mm works out to 0 to .0004". This doesn't sound right. Chevrolet's production spec for the CV guide clearance is .001" to .0027" with a service limit of high limit production plus .001". Their spec for cast iron heads with integral guides is about the same. My target range was .001"-.0015".

With modern viton seals replacing the junky OE nitrile seals oil consumption went from a quart every 200 to a quart maybe every 5000. I drive so few miles between annual oil changes I can hardly measure it. The old guides were SEVERELY worn. Don't know why as the design should not yield much side force, but the car does have over 4000 miles (out of about 74K total) of race track hot laps.
No measureable wear on the aluminum/silicon bores, but the guides were shot. As long as the bores don't score, they seem to last forever. Mercedes licensed the Reynolds/GM cylinder bore technology (as did Porsche and BMW) used on the Vega 140 and Cosworth Vega engines and developed it from there.

Duke