1st, i go buy a box of those screws ( i always seem to strip a few). second, i know the thread pitch doesnt match, but i drill and tap for 1/4-20 threads (its a close match) in the holes of the wheels. i only put 5 on each side, and i line them up with the lug pattern. then, mount the tires up. then i ever so slightly run a 1/8 or 3/16" drill thruogh the hole in the rim and about a 1/4-3/8" deep into the bead of the tire. then, just turn the screws in with a 1/4" ratchet and socket.
--chad