You ask "Any chance my battery might be just on the weak side? I measure 6V, and it cranks the engine fine, but its not the newest."
Sure a weak battery can cause a poor spark ESPECIALY under cranking conditions when battery voltage is reduced. Depending on Condition of battery,,,,,,,,,,Condition of and current draw of starter motor,,,,,,,,,,,,,Faulty or too small cables or connections or switch/solenoid voltage drops,,,,,,,,,,,,,Condition and compression of engine and how hard to crank,,,,,,,,,,,,,,,WHILE CRANKING Id expect the battery voltage to drop to maybe 4.5 to 5 or so volts but if much below that the spark may be weak. At 67 degrees a full charged 6 volt FLA battery at rest and stabilized would be 6.3 volts and again when it cranking (subject to all the above) it might drop to 4.5 or a tad less to 5 volts.
A shop can do a Load Test for free on your battery, you might want to take advantage of that if you suspect a weak battery !!!!!!!!!!!!!
If you can pull a plug and observe its spark WHILE CRANKING it should be visible and blue and NOT any faint thin wimpy hard to even see yellow spark.
Good quality points gapped correct with a good condenser (I've seen many bad out of the box grrrrrrrrr) and sufficient coil voltage (say 4.5 to 5 when cranking with no ballast and a 6 volt coil) ought to do the job
DISCLAIMER again I'm NOT a Ford man and no idea if any ballast is used and if so its resistance and voltage drop or the correct coil input voltage and if there's any by pass when cranking SO ASK A FORD MAN NOT ME
John T