brake up grade 1987 c-10 1/2 ton

[siataspring850]

I am going to upgrade my brakes from manual to power. I read in a recent post I would need to change out my brake pedal. Is this true?
My truck is manual tranny with factory front disk brake so it has a proportioning valve block I think I can keep the proportioning valve in place and just add the booster with brackets add a vacuum line from the carb base plate and its done. any thoughts would be appreciated

 

[Keith Seymore]

You will need to change the brake pedal ratio from 6.5:1 to 4.5:1.

There may already be the correct hole in the pedal, so you may or may not need to change the pedal itself to accomplish the ratio change.

I just went the other way on my Chevelle (from power to manual) and both holes were present in the pedal arm.

K

 

[Keith Seymore]

Here is the brake chart for 1986, which is the same as 87 (I'm at work and I happened to have this one scanned).

You can see the difference between manual brakes JB1 and power brakes JB3, line by line and part number by part number.

K

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[siataspring850]

thank you. I am going to have to pull the swing pedals in order to see if there is an extra hole. I think I did this once years ago and drilled to hole to match my needs. Once I pull the pedals I am committed to the project. I am pulling the trany today so power brakes will be next up.