If you have no problems, you can use what you have.
When GM converted to 12V in about 1955-1956, there was a problem. During starting, the starter takes a huge amount of the voltage/amperage until motor starts. When motor starts, starter no longer draws voltage, then voltage to the coil/points was too much. They like about 8V or they will burn out fairly quickly. So GM added what is called a "bypass" system. All other makers did the same for many years with some improvements. Owners of older trucks who convert to 12V must also add this bypass. This is done with the parts I listed. Those parts allow full available voltage to starter and points during cranking. When motor starts, voltage is reduced to points to about 8V thru a resistor. Ballast resistor. During cranking the ballast resistor is "bypassed" so full available voltage is given to points as mentioned. Then ballast resistor gets back in the system when motor starts.
The method used on your truck can be OK. It has less parts. Just an internally resisted coil. This coil provides the 8V to the points to protect them. But it is always 8V and during cranking of 12V starter motor,, the voltage to points drops and can create hard starting. This will show up on cold days when battery and oil flow is sluggish. Some motor parts may shrink in the wrong place. If there is also bad connections, corrosion or a weak battery.....no starting.
So you see why we say if you have no problems you are OK, but if you do, you will know why.
Last edited by bartamos; 01/08/2023 10:03 PM.
