1980 K100 Cabover Project/daily runner

You have to change the starter to complete this swap, that is the reason for the parallel switch is to switch on the 24 volts to the starter.

 

SmokingCat is right, I assumed you had already installed a 12 volt starter. If you are installing the new starter alone, I suggest to get a longer bolt (size of starter mounting bolt), cut the head off the bolt, use a hacksaw to cut a notch in the sawed off end. Screw the bolt into one of the starter mounts. Now you can slip the starter in, the headless bolt will hold the starter in place so you can install two mounting bolts, then remove the headless bolt with a blade screwdriver and finish.

 

I can't remember the access on a K100 but I remember the reach was too far for me to hold the starter with one hand and start a mounting bolt with the other on my Peterbilt

 

I hope you did not do that on account of me. If it is not broke do not fix it would be my motto. You will find so many things wrong there is no need to go searching for more. Just mentioned that so if you were still 24V you did not stay with it.
Hats off to these guys restoring but I thought you are trying to put this thing on the road making an income. I would put that money into something like 4 30/30 brake chambers or tires instead of replacing a starter that works.
Mostly said so you paid attention to the cable connections and did not create your own problem. I often wrap masking tape around them and label them. If there is a gob of wires on one terminal tie strap them all together ASAP.

 

My Pete had a 12/24 system when I bought it. The first problem I has was with the series/parallel switch, I removed it and I bought a 12 volt starter and used my existing 4 six volt batteries. Quick easy upgrade. Beside the starter, I bought two longer battery cables to replace the short ones that went to the series/parallel switch.

 

I recommend you consider Centramatic balancer's. After you wear out your first pair of steering tires, put the Centramatic on with your new steer tires. I got almost double the mileage on my steer tires compared to a previous set of new steer tires alone. I then put Centramatics on my drive axles with excellent results. The only downside, you can't run 3 rail chains. I was able to get by with 4 single chains on the rear axle, two singles on the front driver and ofcourse two singles on the trailer. I was usually able to get by with one single chain on each axle plus two on the trailer. I was able to hang 6 singles in less than 30 min.

 

I'd say forget centramatics. They're useless don't waste your money. I've got some piled up somewhere I took off years ago.

If you want balanced tires dump some counteract ceramic beads in them when you're mounting. That's the only good way to balance truck tires.