Proportion valve question

[Toad455]

I'm getting ready to blast and paint my frame for my 78 C10 2wd. I want to do all the brake lines while everything is easy to get to. I have a rear disc set up I'll be using and I'm unsure of what direct "bolt on" proportion valve and booster to use. I have done a lot of research already and am still not sure. I do not want the valve to be mounted on the master ( I don't want to have to make custom lines), I want it in the factory location if possible. A lot recommend the "PV2" valve, but it appears to be a generic valve and looks like it may be made overseas, not sure. Has anyone used this or any other that is a direct bolt on with success? Can I use a factory type booster with the factory master? There's so much on this topic that I'm unsure on what to do, ..

 

[Toad455]

Now I'm seeing the PV2 valve is for disc/drum and the PV4 or PV72 are both being used but I'm trying to find out the difference.

 

[Rustisbest]

I used this one on mine with a C3 Corvette master cylinder. Line sizes and mounts just like factory.

Right Stuff Detailing PV72 Right Stuff Detailing Brake Proportioning Valves and Blocks | Summit Racing

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[Toad455]

I used this one on mine with a C3 Corvette master cylinder. Line sizes and mounts just like factory.

Right Stuff Detailing PV72 Right Stuff Detailing Brake Proportioning Valves and Blocks | Summit Racing

Free Shipping - Right Stuff Detailing Brake Proportioning Valves and Blocks with qualifying orders of $109. Shop Brake Proportioning Valves and Distribution Blocks at Summit Racing.

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Thanks much for the reply and info. How does it do when you get down on them hard? Do you know the difference between the PV72 and the PV4? Both show the same line sizes and disc/disc. Maybe different pressures? I searched for several hours and all I found was somebody that said they used the PV72 and the rears were locking up early so he had to use an inline valve to regulate the pressure.

 

[Toad455]

What year C3 fits? I searched C3 Vette and it shows they ran from 1967 to 1982. Thanks.

 

[Rustisbest]

Thanks much for the reply and info. How does it do when you get down on them hard? Do you know the difference between the PV72 and the PV4? Both show the same line sizes and disc/disc. Maybe different pressures? I searched for several hours and all I found was somebody that said they used the PV72 and the rears were locking up early so he had to use an inline valve to regulate the pressure.

I don't know the difference if there is one. Right Stuff didnt show a PV4 when I was looking so it may just be the way they number theirs.
Master cylinder # was NMC2300 from Napa...79 Corvette, 1 1/8" bore for power brakes. The 1" bore is for manual brakes and has a deeper center portion on the piston for the push rod.
No lockup with mine-they do have a more linear feel than with drums though. BUT there's a lot of factors that can change the bias-caliper and rotor diameter, weight, ride height, tire size, etc.
Calipers I used were 1.89" with an 11" rotor, it's lowered with a little rake, rear tires are bigger than the front. I may have just got lucky.

 

[Toad455]

Thanks much again for the reply and info, sounds good. Are you running the factory truck booster? Mine will sit factory height (level) with a larger tire in the rear also. I have the kit that uses 76 Eldorado calipers and Astro van front rotors for the rear. I appreciate the part numbers, I'll go with that and see how it turns out.

 

[Rustisbest]

You're welcome. As far as I know the booster is the factory one from 79

 

[Ricko1966]

Thanks much again for the reply and info, sounds good. Are you running the factory truck booster? Mine will sit factory height (level) with a larger tire in the rear also. I have the kit that uses 76 Eldorado calipers and Astro van front rotors for the rear. I appreciate the part numbers, I'll go with that and see how it turns out.

The booster doesn't know the difference between disc drum vs. disc disc so reuse the booster you have.

 

[Toad455]

It's been bad since the mid 90's ha, so I have to buy one anyhow. I was wondering how the Vette Master bolted on but I see now they are a bolt on.