I have seen quite a few articles in the archives about this, bit I still have a basic question about the front drum to disc conversion. My 69 had power drum and now has been converted to a standard disc brake setup from a 69 with discs. The only missing items are the plumbing and proportioning valve. I understand it needs replaced, but which approach would be best? I could use the one from the donor (junkyard for many years) and risk the possibility that it is rusted and not functional. I think I can buy a new valve although I am still not sure since I can't yet locate one. Another option is the use an adjustable valve, but it appears that they are intented to be inserted into the rear line only. Does that mean that I use the original valve also? Some suggestions from people with experience could really save me headaches, and I would probably go with a new one if I could find a source.

Does it look like this (http://www.yearone.com/serverfiles/part.asp?pid=RSV68&c=0&e=0&cat=0&hid=018AC48153) ?

Or here.
http://www.ss396.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=396&Product_Code=FPV-89

I have never seen this valve, but I was under the impression that the proportioning valve was part of the junction block (don't know the correct name) mounted down on the frame where the front and rear plumbing meets. The donor car will still have whatever was on it stock but I will have to check it. Please explain to me what components must be there and the correct terminology for them. Does the junction block do more than just provide a place to connect lines? From what I see the valve you both are referring to goes between the master cylinder and the junction block.

Originally posted by eduardo69chevelle:
I have never seen this valve, but I was under the impression that the proportioning valve was part of the junction block (don't know the correct name) mounted down on the frame where the front and rear plumbing meets. The donor car will still have whatever was on it stock but I will have to check it. Please explain to me what components must be there and the correct terminology for them. Does the junction block do more than just provide a place to connect lines? From what I see the valve you both are referring to goes between the master cylinder and the junction block. The important things are that you locate a proportioning valve, not a junction block. As I understand, the difference is that the drum brakes retain pressure in the lines and the discs don't. There is a check valve in the proportioning valve that accomplishes this. You should also be looking for a valve from a car with similar weight distribution, so that it will send the right amount of fluid to each end of the car. I have seen the correct valves in various suppliers catalogs for varying prices, so I know that they are still available new if that's your preference.

Good Luck