If I were to buy a conversion kitfor dics brakes such as the one Chevy Duty sells. Don't I also have to get and updated master cylinder with booster. The truck has the original 250 six. Where do I get the vacuum from.
Yup, You need a masterCylinder, and proportioning valve. It dosn't necessarly need to have power assist, but most prefer it. Not knowing much about the inline six I'm probably not much help. But if it's like the V8's, the vacume supply T is on the intake manifold. If you have none, or there is not enough vacume ports available, you can get a multi-feed adapter that should fit. (Check NPD for Chevelle's) Dennis
I just did this to my '66. I think buying the booster is a waste of money - you don't need it. I have disc brakes on the front, drum on the rear and the truck stops on a dime. Sorry Chevy Duty, but Early Classics made this process very easy - I also changed the lugs from 6 to 5 on 5 and dropped the front 2 and half inches. Did the whole job in a weekend. Paul
I converted to discs in front and all I had to do was install a master cylinder from a 71-72 chevy 1/2 ton pickup. It pretty much bolts right up. You can score one at a junkyard, which should come with a prop. valve, for about $25, which is what I did. Most auto parts stores sell the master cylinder for $15-25 rebuilt, which costs less than buying a rebuild kit for the used one. Just pick what works best for ya! Also, the manual brakes are working just fine for me. If you do want to install a brake booster on your six, all you have to do is tap into the intake manifold, if one doesn't already exist, install a vacuum port, and hook up the booster. I takes all of 1/2 an hour to modify. P.S. I wouldn't recommend using your old single master cylinder at all. You're just asking for trouble.