Left me stranded just a half mile from my house tonight.  I was driving under power and suddenly she just quit on me.  Tried to get it started again while coasting, no go.  Fortunately had enough momentum to get her into a grocery store parking lot.  Pretty sure it is a no spark situation.  I can see fuel squirting into the primaries and the cranking is very smooth and consistent, not catching at all.  This happened once years ago and I got it towed to my house.  It was the HEI module that time.  Since the symptoms were so similar tonight I took a chance and bought a cheap module from the parts store down the street (even had to borrow a 1/4" socket from them to get the rotor off) and replaced it i the parking lot, under the light of the sodium lamps.  Still no go.  I decided the parking lot repair was not going to happen, so I got it towed home.  All I've done so far is put a voltmeter on the primary wire to the dist and noted that it was 11.4 volts.  Is that low?  I'm assuming even if it is low, it should still be enough to fire the coil?  Other than that, I'm thinking the next two things to look at are the coil and the pickup mechanism.  The coil is only about a year old, but the pickup is original to this dist.  

Pull a plug wire and check for spark before going any further.
The "Batt" wire on the dist cap connector should have battery voltage anytime the key is on, AND while cranking. Be sure to check voltage while cranking. You might have it there with the key on, but might loose it while cranking. Also, check it several time while turning the key on/off, and see that it gives the same reading each time.
Coils normally don't fail instantly like that, but it could happen.
The pole piece(pickup) can certainly fail like that, with no/little warning. Check the wires going to it form the module...if they look weird, or you can see bare wires, that's your problem.
Can't recommend any particular aftermarket dist., BUT...if you find the pole piece is bad, replacing it, and the coil, along with the new module you already replaced, would give you basically a new dist anyway. The mechanical part of the dist is just hardware....unless it's broken physically, there's really not much to fail on that.
Sorry about the breakdown, but glad you were close to home, and not 1000 miles away!

Thanks, Joel.  After having the batt on trickle charge all night I'm up to 11.6 with key on Run and it goes down to about 9.5 while it's cranking.  I pulled #1 plug wire at the plug and leaned the boot against the stearing gear box so I could see a spark while my wife cranked - nothing.  (embarrassed to ask, but what is the correct, safe way to check?  I've been shocked a few times doing it wrong).  So pretty sure it's a no-spark issue.  And I think it has to be the coil or the pickup or something else electrical in the dist.  I'm going to get the coil tested at the parts store and if it comes up good, I'm just going to get a new dist.  

Sorry to hear of your troubles Dave. I can attest that getting towed home is not a happy experience. I bought a DUI this summer but have not used it yet. They are very well made and a great company to deal with. I think it will fit under the shielding. Look forward to learning from your misfortune if you don't mind.

Hey Dave  I have a distributor you can use to test, if you what to illuminate that as the problem.

|UPDATED|10/23/2013 8:03:52 PM (AZT)|/UPDATED|

Thanks guys!  Greg, I'll definitely keep you posted.  Lesson #1 I've already posted: don't buy the knock-off Chinese HEI's.  Even if this one is not the problem, it's still not a very well made part.  I've always had concerns about things like the connectors on this unit - just not quality stuff.  Sounds like you've made it past that lesson by buying the DUI - it does seem like a very good unit based on stuff I've read.  And I think you're right that it will fit under the shielding, their FAQs say it has the same dims as stock.  How come you haven't installed yet?  

I always use a #2phillips scredriver with insulated handle.  I insert into the plug boot and then hold the handle of screwdriver to get the metal a 1'4" or less from a good ground

|UPDATED|10/24/2013 6:17:51 AM (AZT)|/UPDATED|

A battery that has been charged all night should have at LEAST 12.5 volts. Voltage under around 10v while cranking leans to the battery not being good. Doubt it is a ground problem, but you can check anyway. Also doubt the low voltage is causing it to die, and not run now, but the battery does need to be tested/replaced.
On the other hand...low voltage and electronics is a bad combo. If you can get another car up to it, and some jumper cables, you might give that a quick shot to see if the low voltage is keeping it from starting...


|UPDATED|10/24/2013 9:16:06 AM (AZT)|/UPDATED|

I used this company for my distributor on my 74. Seems to be a very well built unit and lifetime guarantees, and the best part very reasonable priced.

Just thinking. If your Alt is not charging the battery properly, and the battery is now bad. if you where driving with running lights or lights the voltage would drop to a point the car will die. the battery can have a bad cell. once again at idle the alt may not be producing the voltage needed to keep it running. when you try to start it is it cranking slow?