Valve Notes:
Now available the 1970 disc/drum and 71-72 drum GM A-Body Distribution Blocks. This block was used on all 1970 cars, either disc or drum, and 1971-72 drum only cars. The disc cars went to a completely different valve. This block is located down on the frame below the master cylinder. This is not a proportioning valve; it does not hold off pressure unless there is a loss of pressure in either the front or rear Brakes, then it will contact the brake warning light in the dash.

In 1968-69 and 70-72, this block is used on all drum cars and in 1967-70 with the round hold-off valve at the master on disc brake cars. In 1971, the disc brake cars use a different valve and the drum brake applications continue to use this valve. This block gives equal pressure to the front and rear Brakes and is also great for 4 wheel disc applications. 1968-69 and 70-72 are very similar valves except the fitting sizes change for the different year brake lines.
This item is an exact reproduction featuring a brass body, the correct bracket, gold plating and working insides. You will also find with current manufacturing procedures, the reproduction has no tool stamping marks and the edges of the part are much cleaner than the original.
GM Notes:
1967-70 cars all came standard with a dual master cylinder and drum Brakes, and 1967 was the first year for optional disc Brakes. If the car had either drum or disc Brakes, there was a distribution block with a built-in brake warning switch down on the frame below the master cylinder. From 1967-69, if the car had factory disc Brakes, it used the drum distribution block in conjunction with a disc brake hold-off valve, which made the disc cars a 2 part valve system. In 1970, GM added a third valve in the rear line for brake correction, so the 1970 system had three valves. For cars converting to disc Brakes, replacement after market 1 piece valves are also available. Conversion valves will not plumb into existing factory lines.
Prop. Valve Brackets are available for all cars with disc conversions.