Master Cylinder and Proportioning valve

[Garagedude]

Alright I am in the middle of doing my disk brake conversion and have read other threads about it but am still a little lost. I am doing a complete disk brake swap. I have wilwood disk brake conversion on the rear. And a performance online kit for the front that uses Chevelle rotor and Camaro calipers. My question is the truck had complete drum brakes. So I know that the proportioning valve needs to be changed for the disk but will I have to change the Master Cylinder. Some people have told me to use a corvette master cylinder. Is this a good idea.
Here is one I saw on ebay.

The truck is a 70 C10 SBC, TH400, Posi Rearend

http://cgi.ebay.com/ebaymotors/63-67...=p4506.c0.m245

[Bob@ProAuto]

Disc brakes need more fluid to work as compared to the wheel cylinders. You will need a master cylinder designed for 4 wheel discs. And Dual reservoir, for saftey issues.

Depending upon the calipers, you'll need either a 15/16" bore, 1" bore or 1 1/8" bore master cylinder. I'd suggest that you call both companies that you bought parts from and tell them what you have. They should both be able to tell you which bore you'll need.

[prostreet1967]

im going back manual with 4 wheel disc. i found master cylinder at autozone 30 bucks. 73 corvette.

[K5KRAZIE]

When I converted to "stock" 4 wheel disk on my 72 K5 I used a 3/4 ton master/power booster, and stock prop. valve. The rears lock way before the fronts so I think an adjustable prop. for the rear circuit might be a good idea....