[straycat]

I'm in the midst of going from single reservoir master cylinder and power brakes on my 62 Catalina to a dual reservoir master and manual brakes. I mounted the new cylinder in the 2 middle holes in the firewall. I would like to know what the difference is between a manual brake pedal arm and a power brake pedal arm. Pics or illustration would sure help. Did I mount the new master cylinder in the right location? How did the factory change the ratio? Right now I'm 2.6-2.7 ratio going by my measurements.

[Charlie Jones]

The difference is in the length of the pedal arm and the place where it mounts .
The black pedal is manual brakes. The red one is power.

[straycat]

Thanks Charlie the pics help a lot. Do you know what the distance is from the pivot point to the pushrod hole? One of my friends is an old NASCAR team member and thinks the power brake pedal can be shortened. Luckily we have extras to sacrifice.

[Engine-Ear]

Originally Posted by straycat

Right now I'm 2.6-2.7 ratio going by my measurements.

How are you calculating this, and a ratio of what, exactly? (I'm not being a smar tass, I am trying to understand what you mean)

[straycat]

Engine-ear rather than me try to explain check this out. http://knowhow.NAPAonline.com/how-to...ke-pedal-ratio
or just search how to measure brake pedal ratio.

[Engine-Ear]

Thanks, straycat.

[Charlie Jones]

Originally Posted by straycat

Do you know what the distance is from the pivot point to the pushrod hole?

I don't have the manual pedal anymore, sold it.
If you look at the bracket it hangs from , you will see it has two sets of mounting holes . Measure the distance between the holes.
I think if you shorten the upper part by that amount and mount the pedal in the lower set of holes , everything should work OK.
I think that before you consider modifying a brake pedal , you should at least look for a manual brake pedal. They do pop up on E-Bay occasionally and you might also try Pontiac Paradise.

[hobbygto65]

Looks like the brake rod hole is in the same spot in relation to the pedal, you just need to move the pivot point down.

[straycat]

My NASCAR friend showed up with his collection of pedals. One was from a 69 Grand Prix or so it was labeled. Looked like it could work. The pivot area was shorter than a 62s but I had some Teflon spacers laying around that added to each side worked perfectly. (had to drill them to the diameter)The arm rubbed slightly against the column but grinding a little gave the clearance. Installed it in the lower holes in the bracket and the pushrod lined up perfect. Everything seems to work well.