Yup!! You got water everywhere.............how's that for a news flash.

If the inside of the cap was wet, so was the entire inside of the distributor housing. And any other connection to the ignition components. There could be water under the coil module, in the bottom of the distributor housing, at the contacts on the cap, maybe even the spark plugs. If you have a dry, compressed air source you could try blowing it dry. Also, do you have an MSD control box, or similar.............could be another problem area. ALL components need to be thoroughly dried. Maybe even replaced at this point if corrosion has set in.