well mate....all i know (which is very little I admit..)is, that when my head came back from 'The cylinder Head Shop' the ports looked lovely, the guides were profiled off to blend with the ports, and the valves looked very similar to your originals...and the actual seating area was a thin pencil line round the valve and the valve seat had been sort of rounded, with a matching thin seating line...the valves, as far as I'm aware, are standard Yam.
Come on Son...get a grip...you'll miss the start!!
