It was a while ago, and those kits were very available then as well. I bought a custom kit used.
The person I got it from had purchased the kohler flywheel separately, but sold the kit never installing it.
The only thing from the original kit I used was the starter motor and the keyswitch box. Flywheel was not part of the kit. Coils were not part of the kit. Fan shroud / blower housing was not part of the kit I purchased. The kit I got came with the same single coil, but I never even tried it out. It is still sitting around my apartment somewhere.
For testing, I only measured voltage across a battery when my system was running. This is just using a diode for half-wave rectification.
With no accessories "ON", I was getting over 15.5V at at 1350 RPM and at 3050 RPM I was getting 16.55V. With a 1amp fuel pump "ON" I was getting around 14V at 2350 RPM and around 16.4V at 4070RPM.
If I remember correctly, when adding the headlight I was going to use - the voltage stayed withing a reasonable charging range up to around 5k or 5.5k rpm.
Instead of using a regulator, I was just going to add more amperage draw to make sure my charging system did not fry my battery. Then I was planning to tune my Torque Converter to so that it shifted at an RPM appropriate for my gear ratio and charging needs.