Dances with Shrapnel said:
I suggest you try the easy stuff first.
Get some stainless steel safety wire with a sharp pointed cut end. Fashion it into a tiny cork screw shape and go fishng from the intake valve pocket side. They do this in the oil field but on a slightly bigger scale. You could also just try probing around a bit with a straight safety wire.
If that fails to give results consider putting some moderate air pressure to the crankcase; how much pressure, I don't know and maybe others can chime in on this. If over done you could upset the crankshaft seal.
This is one way of doing it, but for best results make sure all the oil is drained out of the head, refit loosely the tappet covers, then remove the timing cover and with an high pressure airline, blow into the oil drain hole that comes from the head.
If necessary, put your finger over each of the holes at the bottom valve spring collar to check that there is no blockage.