This could be considered "normal" and really does not tell you very much
The current path from the battery to the coil is quite long. Far more important is what you have on the "switch side" of the ballast which SHOULD be but probably is NOT within a very few tenths of battery.
Some things to do:
Very first things:
Remove the ECU clean the mount and re-mount with star lock washers. The ECU MUST be grounded MUST
Check
Remove the system connectors, ECU, ballast, and distributor, examine them with a light for corrosion, and work them in/ out several times to scrub clean and to "feel" for tightness.
Check
Run a heavy clip lead from the coil+ terminal to a battery source like the starter relay battery stud and see if you have spark
Check and still no spark and still had only 3 and a half volts across the coil even with the jumper connected to the + battery post.
On a related note, clip your meter to coil + and crank the engine USING THE KEY. This should result in very close to "same as battery" voltage and in no case less than 10V
Check and had 2.98 volts while cranking and no spark
DO NOT forget!!! that the coil HT wire could be bad.
Not familiar with "HT" wire what does "HT" stand for? (excuse the ignorance)
Set you multimeter on low AC that's right, AC volts, and hook the probes to the distributor connector. Crank the engine.........it should generate about 1 volt AC
Check my multimeter is a cheap one and only has "200" and "750" settings, when on "200" and the dizzy was turning it did show an alternation on the meter screen.
Remove the cap and inspect rotor, cap, for moisture, dirt, carbon, inspect the rotor for damage. Remove the rotor and inspect for "punch through" the center (AKA lightning bolt)
Check New stuff, really looks ok
Make SURE LOL that the distributor actually turns!!!
Check, sure does
Check the shaft for play and wobble. Check the pickup and reluctor for strike damage, for rust and debri. Get a .008" feeler gauge (O'Reallys) that's inches not metric. Check the gap between reluctor tip and pickup coil.
Check plus I compared to a spare dizzy and all seems fine
I never can remember which of the two wires..........try them both. With key on, ground one of the two distributor connector wires on the ECU side. Each time should produce one spark.
If none of the above shows up anything, it starts to be a tossup. Check the resistance of the pickup coil in the distributor, which is "not that important." They vary "somewhere" around 200--400 ohms. If a bunch above, or below, or won't produce the 1V test, replace it.
Ohm the pickup coil from each terminal to ground. Should NOT show continuity....IE it should show infinity. Be careful to keep your "fingers" off the probes, as some meters will register your body resistance.
After this, it's almost a tossup. Cheapest is probably a coil, if you "think" the distributor is OK try an ECU. The dealers were supposed to have expensive testers, but many just had "trial" boxes to plug in!!!