I'm hoping someone could help me out. I have a 64 el camino (obviously). It has four wheel drum, manual brakes, with the single well master cylinder. A friend of mine was parting out his 71 el camino and saved me his front disc hardware including: rotors, calipers, spindles, hardline, sheilds, prop valve, and master cylinder and power booster. We were just going to swap everything out but a guy at the pomona swap meet told me that my brake pedal has to much leverage and the brakes would be overly sensitive to the point of dangerous in wet weather. If that is the case what master cylinder/power booster do I use? Can I use a specific master for manual front disc and rear drums? Does anyone know where in the system should an adjustable proportioning valve go? Any info and theories would be helpfull.

Elky lets see if I can help with some of your questions...
If all the parts that you got are in good shape then I would say go ahead with the swap. Some problems that you may encounter are that the hard lines will most likely need to be either tweaked or replaced with new ones so that they will fit properly. Also I am not sure whether the fitting on the front to rear line will work, a call to Right Stuff Detailing @ 1-800-405-2000 can help solve those issues.
The pedal/booster problem should not be that difficult to solve as I have put a 71 booster on a 65 you just have to check the overall travel of the piston rod in relation to the pedal so that you don't bottom out the piston in the MC.
The part about being oversensitive in wet weather is relative on whether you know how to drive and getting used to the added stoping power of the new brakes. This guy was probably old and just can't imagine driving anything that has improved brakes on it. As long as you use the prop valve from the 71 you should be ok just be ready to feel the difference in stopping power!
The proper place to put a adj prop valve is in the brake line that goes between the MC and the 71 prop valve for the rear brakes, this is so you can adjust the rear brakes so they will not lock up before the fronts but I'm sure someone else can go more into this than I can.

J.J. Fig

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MCC member #256

Just went through this changeover on a '72 and the brake pedal has 2 holes for the pushrod connection: one for manual and one for power. The lower hole is used on the power brake applications. When you do this swap be sure to get the stamped spacer that goes into the upper hole on the power brake pedal; this makes up the distance to the brake light switch with the lower pedal position on the power installation. Also, get the brackets for the front brake hoses from the disc brake car; they are thicker to fit the hoses for the disc brakes.

Thankyou JJ and Mr. Wagner, are you sure about there being 2 holes for power or manual brakes on a 64 brake pedal? 64's could not be had with power brakes so I was thinking there would not be a second hole to use. The 2 hole idea was also mentioned on the Master Power Brakes home page - and gave me more questions than answers.

elky64, Sure, power brakes WERE an option in '64 it was RPO # 6-J50 (POWER BRAKES)& there were 37,739 vehicles equipped with it out of 370,834 (US production). This option was available on ALL models in the Chevelle lineup.

The reason for the "two mounting" holes in the brake pedals is that the upper one is used for the manual brake master cylinder which mounts completely in a horizontal plane to the firewall.

Whereas the lower hole is used (by the factory) when the car was equipped with a power brake booster which was tilted a few degrees above the horizontal plane to the firewall which therefore (on the interior side of the firewall) "dropped" the mounting of "pushrod" to the lower hole.

The tip for easier install of power disc brakes onto '64-66 Chevelles (all models) is to use brake lines off of a '67 Chevelle since these are equipped with provision for the dual reservoir ('67-72 power disc brake) master cylinder and are bent correctly for the '64-67 style frame.

Either used or new (cheap insurance)lines will work (GOOD used ones will work).

Thanks, Len

Len thanks for the help! I now feel a little more confident in taking this project on by myself.

elky64, boy!! you sure ARE "more confident". You said so 5 times!! Just kidding (these darn computers!)

This morning after sending my last post I went out and looked at a couple of my cars.

Mind you, these are PROJECT cars I've not really started on yet, so I can't vouch for their ORIGINALITY. But here's what I found..

(1) a '64 2 door wagon, it has the early style "small diameter" factory power booster and 4 wheel drum brakes, with single reservoir. It (booster IS tilted) and the pushrod is in the LOWER hole on the pedal. There IS an upper hole as well.

(2) a '66 2 door Malibu, manual 4 wheel drum, single reservoir, pushrod in upper hole on pedal. There IS a lower hole there as well.

I would hope YOUR car already has both holes so you don't have to swap brake pedals, (or drill the other??).. but if you DO it's not too hard. If you are tackling the rest of the swap, this part is a piece-o-cake.

Good luck. Thanks, Len