70 Chevelle Rear disk brakes, master cylinder recommendation

[Greenchevelless]

I just put s10 rear brakes on my 70 chevelle. They are 1-7/8 piston size. Im running the factory front disk setup. What master cylinder is recommended? Is the stock 1-1/8" disk/drum master fine to use? Also what do I do about the proporton valve thats under the master cylinder?

This is what describes my current brake system. Ive already bypassed the hold off valve on the frame above the rear end.

"The 1970 disc/drum brake system is interesting.

The stock system had a master cylinder, a proportioning valve for the front discbrakes, a distribution block, and a hold off valve for the rear drum brakes.



The proportioning valve was mounted next to the master cylinder and its propose was to proportion the amount of fluid that went to the front disk calipers. It did not affect the rear drum system.

The distribution block was mounted on the frame below the master cylinder/power booster. It proposes was to send fluid to the two front calipers, and the rear drum wheel cylinders. It also had a valve that sensed a pressure imbalance between the two systems. If such an imbalance occurred it turned an idiot light on, on the dash.

The hold off valve for the rear drum system was mounted on the leading edge of the cross member just above the rear axle. The purpose of this valve was to hold off appling the rear drakes so that you did not get premature lockup on the rearbrakes. I believe that this valve was only on the 1970 and that GM fixed the proportioning valve after that year so that the hold off valve was not needed after that"