Master cylinder installation below the floor.

I'm looking at installing a dual master cylinder in place of a single MC (on a vehicle with disc front and drum rear, which isn't working well let me tell you). I've read that a low level MC isntallation will require the 2 psi for the front and 10 psi rear residual valves plus and an adjustable proportioning valve. All Wilwood from Mopac is probably the easiest.

However my question is don't some MC have residual pressure valves built into them do they not? Mine is a Classic Performance Products MC1312. I didn't buy it, it came with the truck.

Yes, 2 and 10.

You will have to ask Classic to make sure, but I think that (aftermarket) disc brake MC that are normally mounted on the fire wall do not have a residual valve.

Most times a OEM proportioning valve works fine, and be sure to bench bled the MC, they are a bear to get the air out when mounted low.

Ok thanks. I think I will use an OEM proportion valve since I've got an extra one in the garage.