It would depend on what the caliper and wheel cylinder sizes. What are the front calipers and rear wheel cylinders?
Kinda need to know a few things . caliper size ( no drag ) etc Wheel cylinder bore fire wall / under floor . power / manual. pedal ratio etc etc . we can say the “ standard master “ is usually a mustang master or Chevy car master , but with the amount of brake issue threads we get , more detail helps putting the system together correctly .
If your not sure on what parts to use, it might be best to buy the whole deal from one of the companys that all fit together. Or buy the brake parts for say a "70 Pontiac Catalina" or a 80s Chevy Impala. If your half way there. Use a adjustable proportion valve and install it on the brake line that goes back to feed the rear drums. Summit Racing SUM-G3905 Summit Racing™ Adjustable Brake Proportioning Valves | Summit Racing Also install a metering block to the line feeding the front discs. Brake Metering-Hold-Off Valve (speedwaymotors.com) Buy the small bottles of brake fluid usually 6 will do the job. Once the bottle of brake fluid is opened, the remaining fluid needs to be tossed.
When plumbing a system that has a manual MC and disc front and drum rears I use a dual MC from a Ford pickup. I think the last year manual disc/drum brakes was offered was 1977.
I used a disc drum on my coupe. I have drums all the way around. Used a 7/8 bore.put the larger Revisor to the front set.
Rock Auto's listings give bore size, whether they're manual or power and whether they're drum/drum, disk/drum or disk/disk. Buy from them or get a part number to take to your parts store. I like '70s Ford intermediates for 15/16 bore, disk/drum, manual brakes on my 2 cars
It might take 50 to get it right. Still, If the car uses an OEM front caliper and matching rear wheel cylinder looking to see what the caliper donor had for a master cylinder bore is probably the best place to start.
I use the Ford applications because of piston sizes and you can get the outlets on either side. They weigh much less than the corvette unit that is commonly used. As is stated, Rock auto is a good source of info. The 7/8 will provide more pressure than the 15/16's or 1" versions. From my exp., I would use either the 15/16's or 7/8's versions. There are some alum versions that were used on disc brake apps that would require a residual pressure valve is so desired.
Mustang masters are nice. The Ford LTD ones have the plumbing on the inboard side, if that helps. I'm using a Mustang/Fairlane on my Ford, plumbing is on the outboard side.
I used one of these mounted to the firewall on my 34. I have discs on the front and a Ford 9” with drums on the rear (no power booster) The master cylinder had 1 1/8” bore for the brakes and the clutch. The clutch was very hard to operate and the brake pedal only went down a little way before becoming hard and to be honest the brakes were not the best. Sleeved the brake side to 15/16” and the clutch to 7/8” I now have a clutch pedal that feels like a factory car and the brake pedal feels the same and I have great brakes too.
The pedal ratio can also be modified to increase or decrease the effort required to generate a specific amount of pressure. A 1" can generate more pressure than a 7/8" at the same pedal effort if the ratio is higher.
The other thing to keep in mind is that given the same amount of input force a smaller bore master will make more pressure at the expense of increased pedal travel.
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