3B,

Thank you so much for helping me with part numbers. After scouring the web, I think I did find the master cylinder you referred to with the 1-1/4" bore. It is a Centric part: 130.80018, which looks to still be available. What do you think? https://centricparts.com/part-detail/13080018

For the wheel cylinders, do you know if the front cylinders can be both used for top and bottom? I ask because my front axle has two wheel cylinders per wheel (top and bottom).

Another question, do you know how to identify GMC medium duty VINs? I say this is a 1966 because thats whats on the title but Id like to know what my VIN means: LV4016026451G
Attachments
wheel1.jpg (161.44 KB, 127 downloads)
wheel2.jpg (155.76 KB, 127 downloads)

1971 Chevy K10
1968 Chevy C50
1966 GMC 4000 Tilt Cab