[Mike52]

What is the proper master cylinder piston size to use for a manual brake system using disc on front with rear drum brakes? This is for a '67 with a front disc brake conversion.

 

[67 Nova Boy]

For a factory 67 Nova front disc/rear drum...it is a 1" bore. The master is for manual disc, not power.

Dave

 

[Sooner1]

What is the proper master cylinder piston size to use for a manual brake system using disc on front with rear drum brakes? This is for a '67 with a front disc brake conversion.

I used a 68-74? Vette manual master on my 66 for awhile. 1” bore and cheap but if you use it you would new a 10# residual pressure valve for the rear line because vettes were disc/disc

Wilwood suggested to me both 7/8 and 15/16 for manual brakes
I like the feel of the 7/8 better on the street. A little softer pedal
I put the 15/16 on the twin turbo 72. I believe I was told it would hold better on a foot brake but I dont remember my physics enough to tell you further lol

I believe wilwood is worth the investment

 

[JIMS63s]

Mike, I went with the wilwood 1" on my manual disc/drum 63 and I wish I had gone smaller bore. Pedal is high and firm but you really have to stand on the pedal to stop quick. Smaller bore will give you more braking pressure with less pedal effort. The pedal will move a little more to move the same amount of fluid but the stopping will be better.