I'm not sure I agree with the lifters NOT opening the valves. I always compress hyd lifters when removed from the head (no oil left inside) which causes a rattle for a while but they always start. When you remove a lifter it can draw in quite a lot of air which is enough to hold the valve open. To prove this point, when this happens turn the engine over by hand for about 20-30 mins and it will fire up. This is because excess oil (and air) have been ejected. I have only just read this thread but Aiden asked in his first post if the lifters were drained.
Regards,
Bryan.
PS. One of these I did left me scratching my head as I used the key on the crank sprocket (for the pulley) as a timing mark after getting confused with a Vauxhall. I didn't try to start it as the valves fouled the head when turning over by hand but realised my error after removing/refitting the cams and sprockets several times