[nikwho]

Hello all,
Quick question about my brake system setup, specifically regarding my master cylinder and proportioning valve. My '59 Apache has a '79 Camaro sub-frame and 10 bolt rear axle. Has stock diameter front cross drilled/slotted rotors with Wilwood dual piston calipers. Just wrapped up an LS1 rear disc brake swap, with matching cross drilled/slotted rotors and single piston calipers.

It currently has the booster/master cylinder/proportioning valve from the same '79 Camaro donor car. I now want to upgrade/replace the booster, master cylinder and proportion valve. I'm pretty happy with the firewall mounted setup, with the Camaro pedal, etc. I'm fairly open to keeping with firewall mounted, or frame mounted setup, though I'm not so sure that the frame mounted setup would fit, given my Camaro sub-frame swap.

So, assuming that I stay with the firewall mounted setup, what should I be looking for regarding master cylinder bore diameter? Booster diameter? Do I need to buy a disc/disc proportioning valve? I've currently got a Wilwood adjustable proportioning valve installed in line with the rear brake line. FWIW, I also have a line lock on the front brakes. My understanding was that the Wilwood adjustable valve would make my setup work, after some tuning, but upon further reading, I have read that the disc/drum proportioning valves (like mine) delay fluid reaching the front brakes, due to drums requiring more time (and fluid?) to actuate.

So, do I need to swap proportioning valves? What master cylinder bore diameter should I seek out? What effect will different bore diameters have on brake/pedal feel? What diameter booster diameter should I look for?

My 383 has about 10:1 compression, with a fairly mild cam that pulls decent, but not a ton of vacuum. I may run more cam in the future, that will decrease vacuum, and may end up needing an electric vacuum pump for the brakes.

Any help would be greatly appreciated!

Nik