Right, as stated above, if your crank sensor is bad, you have no spark at all.
Assuming that you really do have spark everywhere but the 1/4 coil then I would say swap that coil with another, see if the problem moves. If it does, the coil IS bad. If it doesn't, I'm thinking bad ICM.
Of course, that'* assuming that you have the individual Delco coils. If you've got the single Magnavox unit, then you'd just want to either swap in a new coil/ICM assembly, or better yet, upgrade to the Delco system. No better time.
Pretty much though, if you're getting spark on some wires and not others, I think the problem HAS to be either the ICM or coil(*). Someone correct me if I'm wrong, but I can't think of any other scenario.