The truck has already been converted to 12v. I know you can apply 12v to a 6v starter, but that isn't a very good permanent arrangement.
I have over 35000 miles on the back yard rebuild of my 6 volt starter on my converted to 12 volt electrical system truck. I never let it crank more than 5 seconds without a short rest, but my truck probably starts 75 percent of the time in 2 seconds or less because the starter is spinning so much faster on 12 volts.
I see now that just adding a solenoid isn't the answer per klhansen above. I have only run the truck to move it around the yard, and the previous owner the same, so I don't know if the starter and flywheel have been correctly changed.
Believe me, you would know if you had a starter/flywheel mismatch. Much "weeping and gnashing of teeth".
What are the different tooth counts for the 6 vs 12v flywheels? I can put it on the lift, and remove the inspection plate and start counting teeth.
Answered
HERE You don't need to count all the teeth, just measure 10 of them.
