I am beginning to pull together the items required for a conversion from drum to disc brakes on my 70 Chevelle. I have a complete master cylinder, metering valve and proportioning valve setup from a 69 with power disc brakes that I picked up a couple years ago. I know that the metering valve is the same but what about the master cylinder and proportioning valve? My Chevelle is a September build if that makes any difference.

It will work, but as far as I know the '69 master cylinder and metering valve differ in appearance to the '70 model.

I purchase most of my correct brake parts from Inline tube, no problems to speak of so far, link> http://www.inlinetube.com/

The 70 takes a rectangle master cylinder and a similar, but different proportioning valve. The 70 also takes a second metering block that bolts to the rear frame crossmember above the rear axle. The 69 stuff will work, just make sure you get metal lines for a 69 with disc brakes.
The other thing that is different are the brackets that retain the front brake hoses. If you want to cheat so you don't have to change these, use 69 Camaro disc brake hoses. They will mount into the Chevelle drum brake hose brackets on the frame.

This probably won't help you any, but the last three pictures show what the lines look like http://www.1969supersport.com/rockerpanel.html its off from a 1969 chevelle.

Rob

If its not correct in appearance, I would rather not use it.
Looks like my existing distribution block is the same as disc. So I will just pick up a aftermarket master cylinder and metering valve. Is the appearance of these aftermarket products pretty close to original?

The Inline Tube catalog has some very nice stuff. I was surprised to see the amount of detailing products over and above the brake related stuff.

Dan - FYI the "correct" master cylinder for a 70 is not being reproduced. The reproductions don't have the bleeders on the master. Other than that, they are pretty close. Correct casting number of an original is 409.

Thanks. I noticed that the ones listed in the Inline Tube catalog show the bleeders. I will have to give them a call to see if the one for the 70 really does or not.

The 70 takes a rectangle master cylinder and a similar, but different proportioning valve. The 70 also takes a second metering block that bolts to the rear frame crossmember above the rear axle. The 69 stuff will work, just make sure you get metal lines for a 69 with disc brakes.
The other thing that is different are the brackets that retain the front brake hoses. If you want to cheat so you don't have to change these, use 69 Camaro disc brake hoses. They will mount into the Chevelle drum brake hose brackets on the frame.
This is right on the money.

I personnally do not like dealing with InLineTube. They are willing to sell stuff but give you a hard time when things do not go right.

Take a look at this page, about half way down are some good pictures of the master etc.
http://www.leverfamilysite.com/Front_Suspension.htm

Give these guys a call, they rebuild correct originials. Classic Brake Rebuilders of Massachusetts. Talk with John. Their e-mail address is jsg11162@msn.com.