Did you ever find a replacement.? I’m looking for a Master cylinder for a 50 GMC 453 Firetruck. Cant get the rebuild kits for them, so having it reserved is not an option. Later Auto parts is looking for me now, says they have 20 that match crossreference numbers. He said it’s 1-1/2 inch piston. Waiting on him to call back and text me a picture of what they have. Hopefully will work. My old one is a Wagner FD4428.
