Do i need to change the proportioning valve and master cylinder?
...or just the proportioning valve?
...or nothing?

 

What you will need are the Proportioning valve and the Parking brake cables for the 9-bolt swap. The Master cylinder stays unless you want to replace it. I did that swap three years ago.

 

IMO, it'll cost a little more $$$ and a flaring brake lines is a PITA, but I'd throw on linelocks and a prop valve. You can pick up a willwood valve and biondo solenoid for under $90 from summit, then figure $20 for some brake line and fittings. Even if you never drag race the car the linelocks are a ton of fun on a saturday night cruise...

The prop valve will let you get the rear brakes right where YOU want them, and not rely on the factory setting which is designed to keep the *** end from switching positions from the front, and compromises braking distance to keep the rear brakes from NEVER locking up.

 

I'm with Roost on this one. An adjustable prop. valve is nice if you have the time/ability to flare the lines and mount it up properly, and one of my mottos has always been: "Why replace, when you can upgrade?"

There are guys who run the stock disc-drum prop. valve with 4-wheel discs and like it.

 

you don't have to swap the prop valve.