Dennis, This is exactly what I did with my truck. Although Andy seems to disagree about some of that. My truck also had all new brakes, front and rear, drums on both. It stopped great, and straight, with the 69-72 Mustang MC for disc/drum brakes, with the addition of a 10# residual valve in the front brake line for the front drum brakes, (This is an external resid. valve downstream of the internal 2# resid. built into the MC). When I converted to front disc brakes, all I had to do was remove the 10# in-line residual valve, and depend on the built-in 2# residual valve that the Mustang MC came with. As for PROPORTIONING, The front to rear weight distribution of our trucks, when unloaded,(which is mostly how we drive them), is very comparable to the 69 Mustang weight distribution. If, however, you want to be able to better control the proportion of braking going to the rear brakes, then an adjustable proportioning valve installed in the rear brake line will give you that option. I'm trying not to confuse the issue, but relate my experience with my truck, as well as my mechanical experience from back in the early 70's.
Thank you for all the comments, experiences, and advice. I have decided to keep my current 4 wheel drum brakes and install a dual cell master cylinder for this setup. I believe this will work for what I need.
Using a manually adjustable proportioning valve, as Bilbo discusses above, allows you to fine tune front / rear brake bias. A good feature over using a stock prop. valve that doesn't allow for any adjustment. I've used the adjustable prop. valve on two vehicles, pleased with the results in both cases.
Will do. Other truck grumpiness has set in. Truck usually runs fine but I noticed it misses some on idle and when I stop the idle speed goes real low before rebounding to normal. I think about timing, vacuum advance, fuel and vacuum advance lines, and carburetor. On another site it was recommended to check float level. I am using a carter 2100s on my 235. Not sure. Any help? Thanks
Sounds like vacuum issue so this means you must begin (as always) by checking and re adjusting the valves before touching anything else , even if you did them 100 miles ago . Engine hot please .
