Changing from drum to disc
 

I want to change my 70 to front disc. Do I have to add power brakes or brake booster to do so or can I keep the original master cylinder?

Re: Changing from drum to disc
 

You will need a disc brake master.. Power is usually preferred with discs. You will also need a different prop valve

Re: Changing from drum to disc
 

I recommend a complete kit. Mine came from ECE as they have an excellent reputation for customer service, but there are other options as well.

I stuck with the conversion kit that kept the drum brake tie rods and ball joints. This will make everything but the disc parts stock correct year auto parts store replaceable.

Currently my conversion is still manual. I have bought a dual diaphragm 8" booster but have not installed it yet. From GM the manual and power masters are different, but on the booster kit they give you a manual master with an adapter that drops in the pushrod bore that reduces the depth for use with the booster.