Ballast resistor
Bought these two wiring
Hu258a
hu306a
Those are correct , but the engine harness is for a points type ignition, not the electronic one. BUT, it will work fine with the electronic ignition if you have a solid state voltage regulator. That's what is what's working for me in the 64ragtop.
Long, long ago, automakers used a mechanical points style voltage regulator. Not so long ago, the regulator makers introduced solid state technology in the old style case. They look like the original parts in points type distributor cars, but the solid state components work much better, and they are cheaper to make as well. You can tell at a glance, looking at the bottom of the regulator. The old style regulator has a couple of large resistors on the bottom plate, the new solid state regulator has no resistors.
The engine harnesses Year One sells as "modified for electronic ignition" have the wiring and plug for the 1968 (I think) and later "flat pack" regulator.
We're closing in on it, my friend.
ATB
BC