Try checking for spark with the spark plug body held against the engine block; I'm not sure how reliable this test is with the spark plug held against sheetmetal. Another way is to hold the coil wire (that goes to the center of the distributor) a short distance away from the block, taking the spark plug out of the equation completely.

Assuming you really don't have spark, measure the voltage at the positive terminal of the coil with the key in RUN. It should be between 6 and 7 volts; report your results.