If you rebuild your own (very simple I might add), instead of buying a rebuild kit, buy a complete similar rebuilt master cylinder. You can buy the rebuilt master for less money then the rebuild kit. At least that has been my experience.

That's exactly what I did. And here I thought I was being uniquely crafty lol It was actually because I couldn't source a rebuild kit when I did it.

Whitepost. Really fast service. I have sent several over the years. I fedex them there on a Monday morning and have always had them back before Friday. One time I had it back Wed afternoon!. They sleeve them.

Note: If you want the original finish left alone, like on a survivor car, make sure you tell them beforehand so they don't paint it.

Just a heads up. I checked in on mine and they are a little backed up 2 to 3 weeks.

HA! that's a bit better than Karps. They took 4 months on mine. It takes a lot for me to rip on someone, but when a company tells you 3 times over 3 months that it'll be done that very week, we have an issue. I sent my last resleeve to LoneStar brakes and they performed as I expected. They'll get my next one.
Rebuilding a master is a simple gig, but you need to source the best seals you can. Dealing with 2 stroke bikes will teach you this in a hurry.

Hi i just sent today to White Post my GM Moraine Master Cylinder for 1974 Trans am for sleeve and rebuild they told me takes 3 to 4 weeks to returned done but give me the option to pay 25% more and returned in 3 days after received also they told me they painted in cast grey in my case is good because i plan to repainted in black like comes from factory and the cast grey base is good to prevent rust in the future. after receive i posted pics before and after thanks

His is pitted Has to be sleeved.
I sent my og master out to be rebuilt. $35. Came back all Brad lasted It went to Pittsburgh.

I have never had any luck with rebuilt masters even when the cars were only ten years old.
They would work for a month to a year and then started to leak and bleed off pressure.
Since then I have always used new and never had an issue.
I would only trust a quality sleeved master cylinder bore I'm done with honed bore masters.
If one could locate a core from a dry climate area then maybe it might work.

he got it back the other day, there was a small charge to expedite the rebuild, it’s painted and ready to go on the SD. They even had the correct cap for 74, and it was plated factory Correct also.

Nice.
What do they charge for a re-sleeved master