hi,
common problems i have found with the 400 series causing no-spark are broken distributer rotor/cap, or faulty renix igniter module (electronic box the coil sits on),and often crank angle sensor. but check all obvouis things first like h/t leads,engine earth,coil/renix connections,fuse etc..
hope this helps....(if you had access to a good car you can always swap 1 item at a time until you find out whats wrong.)

steve