Would you like to preserve the original disk brake proportioning valve on your 1970 Mustang instead of buying a reproduction part that isn't concours correct? I've finally got all of the needed parts to offer a rebuild kit for the proportioning valve (more correctly called a "brake pressure differential valve") used on the 1970 Mustang equipped with front disk brakes. The kit costs $25 plus shipping. Here's a link to see the details and place an order:
http://www.musclecarresearch.com/valve-kit-khThis valve was used on the following cars equipped with front disk brakes:
1970 Ford Mustang
1970 Mercury Cougar
1970, 1971 Ford Torino
1970, 1971 Ford Fairlane
1970, 1971 Mercury Comet
1970, 1971 Mercury Montego
1972 Ford Pinto station wagon
Please pass the word to other forums! I should have a similar kit available for 1968 and 1969 vehicles, sold at the same price, in a week or so.