My 440 died yesterday, and I would like to avoid throwing parts at it

Thanks, everybody, for your kind and thoughtful suggestions, which are really helping me narrow down the cause.

rustycowll69 wrote: "Sometimes if the chain and gears are bad, you can actually see the rotor, not turning smoothly while cranking."

I really like that suggestion, rustycowll69, and I am going to try that first because I can watch it easily right under the hood, with a starter button across the starter solenoid.

I also like BigBlockMopar's suggestion that I check the coil primary voltage in the ignition "start" position, and compare that to the voltage I get with the primary connected directly to the battery.

And Bulldozer, you got me thinking about how dangerous it is to crank a carbureted engine when a plug might fire while the intake valve is open because the timing is off. Thanks for that.

Also, concerning the coil primary voltage issue, that 6.9 volts is in the ignition "run" position, not "start", so it might be OK. I am going to check it, though, by removing the positive wire from the coil primary and seeing how much voltage it has when floating; then measure the resistance of the coil primary; then calculate with Ohm's law how much voltage drop the coil primary by itself should create, and if I have more voltage drop than that, I will know that I have additional resistance somewhere in the ignition circuit.

I will report back! Thanks again. If I do have to pull the front cover off the 440, I'll be sure to post pictures of the original timing gear and chain before I remove them.