O.k. you have full compression - a clue that the valves are sealing completely. They do need a little play (this is one of the times 'the book' isn't helpful as setting clearances with gauges will usually end up with the adjustable tappets rattling like a machine gun). And I just read my advice - you won't be able to adjust the timing if you can't get it to fire (insert facepalm here) so it'll be trial and error. You had it running straight after getting the head bolted up right?