Testing coil, ignition sytem and components?

You can't read the high-voltage output w/ a common voltmeter. You can read primary and secondary resistances. A better test is probably to see how well it throws a spark. A good coil w/ electronic ignition should be able to throw a spark over a 1" gap in the air. Test this by unplugging the coil wire at the distributor and holding it near an unpainted bolt on the engine, then crank. At the higher compression pressures, it is harder to spark which is why spark gaps are much shorter. Also, why you will first notice spark misses at WOT and low rpm.