Could be a "chicken and egg" problem - meaning it won't idle because the timing is way retarded, can't set timing because it won't idle. First things first. If you know the timing is probably off, just advance it (turn the distributor body clockwise) and see if you can get it to idle smooth enough to work with. The exact setting isn't important - yet. You're just looking for a starting point that'll get it running - then you can dial it in. If it's "way" off you may have to sneak up on it. Tweak the timing, tweak the idle settings, tweak the timing again.... lather, rinse, repeat ... until you get it right.