1951 Z starter rebuild/12 volt conversion

Hey all I have been searching for a while now with no luck so I'm hoping someone can help me out. I have a 1951 Z tractor that had the starter go out, I've already had it refurbished once and I think it's time for a total rebuild. With that being said I think I will be money ahead to get it converted over to 12 volt. I have seen a few starter conversion kits on eBay for the U tractors but no luck on the Z. Are the U and Z starters the same internal wise or are they different, I Know they liked to make things model specific in the 50's. I'm not opposed to keeping the tractor 6 volt but with its starting and electrical system needing completely rebuilt I think I would rather put it to 12 volt if it's doable. I live in northwest Ohio near Toledo so if anyone knows any good shops that will rebuild or convert the starter and generator any suggestions are appreciated. I'm also not opposed to shipping them out to a shop but would like to keep it within a couple hours driving distance. On a side note Im not looking for a lesson on 12 volt conversion's I'm just looking for some input so I can get it done if possible. Any help is much appreciated.

I have 7 letter series MMs, G, U, Z and every one of them is running a 6v starter on 12 volts, all I did was replace the solinoids with the 12v version. A quality rebuilder will put out a quality rebuilt product.

"rebuild or convert the starter and generator"

I have converted my tractors to delco alternator with internal regulator, and got rid of the troublesome, undependable generator regulators.

On a late model Z I used the generator bracket, drilled 2 new holes to move it forward 7/8 inch and transferred generator pulley to alternator. Used original belt

Changed to a NAPA IC14SB coil that needs no resistor. 3 wire alternator and connected #1 pin through a diode to switch side of coil.

Change from positive to negative ground by swapping coil wires (- now goes to side of distributor) and ammeter leads. Connect L and Batt wires from old regulator to large stud on rear of alternator.

Starter will turn same direction either polarity.

Thank you for the input, the big concern with the starter is I was always told that 12 volts would burn up the starter unless converted. But after reading up it seems like that might not be as big a concern as I first thought. I will definitely be using this when I go to convert the tractor.

I sent you an email.

OUt of around 30 tractor that I have only one has a true 12 volt starter on it and well it has it because that was what it was when new. All the others ones where 6 volt when new and well they have been 12 volts for decades and well they still have 6 volt starter and have had for decades. Big thing is not to have them crank over for say more then a minute at a time if that long. Even a true 12 volt starter will burn up if you crank and engine over for more then a minute at a time. Starter motors are and always have designed as short term run motors and run them for long they over heat and burn up simple as that

Never done a conversion to alternator. All my MM's stay original 6v or 12v. No sense creating a problem . If you need to feed a starter with 12 won't damage it unless continual cranking. 12v higher voltage with less current.

Have many tractors with 6V starters on 12V for years and years. The wiring in a 6V starter is heavier than the wiring in a 12V starter. Any re builder that is trying to tell you it has to be redone is trying to get into your pocket book.
rvirgil gave you some good advice, but if you want to keep it original with a generator then just put a 12V regulator on it.
MMDEL

This is how I used a GM Delcotron Alternator on my ZAS.

r