Yes for manual brakes you definitely need to use a manual brake master cylinder with a smaller bore.

 

I believe that the 1973 master cylinder for non-power brakes is recommended. It will have the proper reservoir size and proper bore diameter.

 

1973 What? I was told corvette but it shows to be 1" from what I found so far.

 

I bought a 73 or 74 malibu manual brake master cylinder for both my 66 and 70 chevelles. It should have a 1" bore and its got the deep hole so your manual brake pushed will work. Some of the power brake master cylinders have a shallow dimple where the p ushrod hits. Jim

 

This the correct one Jim? Brake Master Cylinder NMC P2071 | NAPA Auto Parts

 

1" bore will need more pedal ratio then the stock manual ratio of 6:1 to work well. You might be able to lower the pedal an inch or more by sistering another brake pedal to the existing one.. You can weld them together but I've bolted them with excellent results.

Nothing better then getting a manual brake system right but it will take work, excellent modulation...

Like Jim said, make sure it's a deep hole master...

 

I used the Wilwood 7/8 bore on my T-Bird, with 4 wheel manual discs. It is still leaves something to be desired. It was the smallest bore I could find.

 

Didnt the factory manual disk brake A bodies use a M/C with a 1" bore? A buddy of mines 70 oldsmobile W33 car is manual front disk and it stops just fine and I looked up his M/C and it shows a 1" bore also?