[ImperialCrown]

The resistance ranges given are correct. Pick up coil resistance will vary greatly with temperature.
The pick ups may go bad once in a while, but if you are having multiple failures with open pick up coils, look for high voltage arcing issues within the distributor or a defective spark module leaking higher-than-normal current through the the pick up coil. The pickup is just a magnetic 'sense' and to/from current should be low microamps (uA).
Worn distributor shafts can cause the reluctor to hit the coil pole.
Wrong angles can cause reluctor/pole collisions when the mounting plate advances, but is OK at rest. If you have to bend the pole piece out of the box, that is a problem.

 

[fjb37]

You cannot tell if an inductance is good or not by measuring its resistance. That will only tell you if it is "open" or not. One shorted turn will kill a coil. Just my $0.02.

FredB

 

[ImperialCrown]

Moving the pick up plate for vacuum/centrifugal spark advance will flex the 2 wires going to it and eventually break the stranded wires inside. When checking coil resistance, move the connector wires and see if the resistance changes. If it does, replace the pick up. The resistance value should sit fairly still.
A proper test of a coil would be to watch the inductive 'kick' on a scope after removing a test voltage from the coil.

 

[Edric]

I have an 88 d100 v6 which has been plagued with ignition issues, and as was mentioned earlier, any arcing in there hitting that pickup is pretty much the worst thing and only real way to fry a pickup coil, found out the hard way. I would be deeply embarrassed to let any of you see my "rebuild" job on my dizzy, though... The reluctor wheel at one point freed itself of its mount plate, nothing a $3 roll of quicksteel couldn't take care of. Anyway, with he reluctor firmly back in place I ran some tests with 2 different pickup coils, one testing about 600 ohms and the other ~1100 ohms (both cold) and despite the variance both ran identically. I'm assuming that as long as the pickup coil signal resistence falls within a min/max range needed for the pcm to sense it, then it's doing its job, so long as there's no flaky wiring or any intermittent crap.

I am interested in the G.M. HEI modification, I've heard a bit of it but still reading up on my truck.. I love my 88 Dodge, but those TBI models are an eccentric lot. I've always been into engines, but the last 6 months owning this thing have been extremely educational from a diagnostic standpoint (you have no idea... Wait no you probably do).