I am converting my power drum setup to 4 wheel power discs on my 67 and not sure what type of master cylinder I need(still using the stock booster). I figure I need one without the residual pressure valve for both the front and rear, and an adjustable rear proportioning valve...is there anything else I would need? What about the bore size?

I got new stainless brake lines for the front and rear, with stainless braided flex hoses. The discs are 11" rotors with GM metric calipers front and rear.

I also plan on using a line lock in the front brake line.

what about the stock distribution block, can I get rid of it? What is the purpouse of that wire that goes to it? Can I do away with it and run a line lock that has 2 outlets and run both my front brake lines from the line lock

I run a 1" MC with 4 wheel manual disc. I think with power assist you can go larger dia....but I would go to the Wilwood site to make certain.

I removed my stock combination valve iirc, but haven't looked at it in awhile. I definitely remember being happy to do away with a rats nest in that area:). And then messing it back up with line lock and prop valve;).

I am running a 1 1/8" bore master cylinder in my Wilwood 4 wheel disc brake set up. I used a combination valve, it replaces all the other stock valves. The wire is for the brake fluid warning light. If there is a leak in your lines in either the front or rear the piston within the combination valve touches an electrical contact which causes the parking brake lamp to light up on your instrument panel. This light also comes on when you apply your parking (E) brake. This configuration works great.

http://i10.photobucket.com/albums/a130/z282nv/Joes1969ChevroletCamaro004.jpg

I went with a stock type replacement master cylinder for a late 70s Trans Am with 4 wheel discs. Cheap and readily available from any auto parts store. My setup uses Wilwood copys of stock GM calipers. Large type like what Chevy used on the 69 & later Camaros and Metric type on the rear. Combination valve like Joe is using with a stock booster. Stock GM front rotors & stock Trans Am rear rotors on the back. Had to lightly machine the center holes in the rear rotors to fit over the 12 bolt axles.

so looks like I'm going to run a 70's type 1 1/8 master for power brakes that came on a car with 4 wheel disc(70 corvette?). I'm going to toss the stock combination valve and use an adjustable proportioning valve for the rear brakes, and a line lock (with 1 inlet and 3 outlets) for the front brakes.

do I really need a hold off valve since i'm running 4 wheel disc?

do I really need a hold off valve since i'm running 4 wheel disc?

I do not think so considering your going with an adjustable proportioning valve for the rear...check this site out.

http://www.hotrodheaven.com/tech/brakes/brakes7_index.htm

I am converting my power drum setup to 4 wheel power discs on my 67 and not sure what type of master cylinder I need(still using the stock booster). I figure I need one without the residual pressure valve for both the front and rear, and an adjustable rear proportioning valve...is there anything else I would need? What about the bore size?

I got new stainless brake lines for the front and rear, with stainless braided flex hoses. The discs are 11" rotors with GM metric calipers front and rear.

I also plan on using a line lock in the front brake line.

what about the stock distribution block, can I get rid of it? What is the purpouse of that wire that goes to it? Can I do away with it and run a line lock that has 2 outlets and run both my front brake lines from the line lock

You really need to do a little research on this. You need to know the diameters of the pistons in the calipers (front and rear) and then choose a MC that will provide the proper amount of line pressure and pedal travel to effectively operate the calipers. Your choice of a 1 1/8 bore MC might be right on the money, or it might be way off. It's also important to have properly matched front and rear calipers, which you might have, but I'm just saying.

Your stock dist block has a switch in it which illuminates the brake warning light on your dash. The switch is tripped when there's a problem with system pressure between the fronts and the rears.

You don't need a hold off valve with a 4 disc system. If your car is a factory 4 drum system there wouldn't be one there anyway.

Since you are using GM metric calipers, I would try to find out what they fit from the factory and then see what master cylinder went on the car. Then you can check the bore size of the master cylinder. Just remember smaller bore , more pressure. Bigger bore , less pressure.