Manual Master cylinder for 70 Chevelle

[Greenchevelless]

I have 70 Chevelle with OEM front disc brakes, late model s10 rear Disc brakes. Been running a with a booster and 1-1/8 master cylinder but never had enough brakes with the cam i was running, and now im switching to a larger cam. Im ditching the power booster and going full manual. I already have a universal 1" bore corvette style master cylinder but im unsure which port is front and which is rear, I pulled the pistons and the primary piston is the rear port so im guessing this should go to the front brakes.
Im also on the fence whether or not that a 1" bore master cylinder is adequate or if i should go to 15/16 or 7/8.

This is the master cylinder i already have.
https://www.performanceonline.com/Disc-brake-Master-Cylinder-Proportioning-Valve-Kit/

[Randy67]

On the Corvette master cylinder (1967-76), front port is for the front brakes, rear for rear. 1" bore should work with the brakes you have now.

[skybu]

I cant imagine that 1" master wouldn't work as long as you have a 6:1 pedal ratio. I am using almost the same combo with 12" wildwood disk in front and factory drums on rear. I have crazy stopping power with normal non-power brake pedal effort. Its better to stick with the larger 1" bore if you can to get the increased fluid volume.

[andrewb70]

If you want an inexpensive 15/16" option, check out a 79 Malibu with manual brakes.

Andrew