You may want to try this to make sure the coil is good. You may show good power going in but not so good coming out.
If you want to "bench" test a coil, remove wires, attach a hot 12 volt to the battery (batt, +, etc.) terminal. Then attach a wire to the ignition (ign) terminal and touch ground and remove. Should throw a spark from the high tension lead with each application of 12v and removal. The ground wire basically imitates the function of the ignition points/module. If the high tension lead terminal is gapped a reasonable amount from the engine, there should be a bright white spark. Weak or orange spark indicates (low voltage...or) bad coil output
If you want to "bench" test a coil, remove wires, attach a hot 12 volt to the battery (batt, +, etc.) terminal. Then attach a wire to the ignition (ign) terminal and touch ground and remove. Should throw a spark from the high tension lead with each application of 12v and removal. The ground wire basically imitates the function of the ignition points/module. If the high tension lead terminal is gapped a reasonable amount from the engine, there should be a bright white spark. Weak or orange spark indicates (low voltage...or) bad coil output