Coils

The old FAQ devotes pages and pages to coils. I've researched the statements and assertions that are made about the topic and cooked 'em down to this:
If your bike is a Z or KZ A1 thru A5 it uses a ballast resistor in series with the coils, which are marked "ZC005-TR12V". If you are planning to replace your coils, whatever configuration you are planing to use, the total resistance should remain the same, or nearly so. For any of these bikes (A1 thru A5) replacing the original coils with modern 3 OHM coils will allow you to delete the ballast resistor entirely.

I'll give one first hand example: My '81 KZ1300-A3 had a 1.7 OHM ballast resistor in series with a 1.6 OHM "ZC005-TR12V" coil for a total resistance of 3.3 OHMs. I replaced the coils with 3 OHM Dyna brand coils and eliminated the ballast resistor. That was fifteen years ago.

Starting with model year '83 the ZNs and possibly the ZGs substituted a different ignition coil without changing the part number. This new coil is labled "ZC006-TR12V" and measures 2.6 OHMs primary resistance. No ZNs and I speculate that none of the ZGs use a ballast resistor. (Need some help. Any ZG owners in the room?)

I cannot say I'm solid on this information. If you've first hand information, that's contrary to any of this I'd like to hear it.

Here's a spread sheet I've complied: 

Comments?
Bill