Master cylinder for 4 wheel manual disc?

What is a good master cylinder to run with 4 wheel manual disc brakes. I am putting together a rear disc setup for the Dana 60 Im putting together right now. I am using GM metric calipers and using 1980's Diplomat front disc brakes. I also ordered a adjustable propotioning valve. I was running stock rear drums and the Diplomat disc up front with a 94 Dodge Ram aluminum master cylinder but the issue I have now is the peddle is very hard. The brakes work ok but it takes both feet to stop it from 125 mph. The Ram master has a really big piston and is actually a power brake master. I was thinking I needed a manual brake master with a smaller piston. I would like to stay with the aluminum master if possible.

I have one of DRdiffs 15/16" on my Dart and it's a ton better than the 1 1/32" that it replaced. If I ever have to replace it I'll use a 7/8" bore. I have gutted factory 73 valve that I use as a distribution block and an adjustable proportioning in the rear line, but it's open all the way.

I should have ordered one from him this morning when I ordered all my Dana 60 parts!

justinp61 is right, Dr. Diff is the man. Good affordable stuff!

And personally I would use calipers off of a Jeep Cherokee. I am not a fan of cross breeding garbage Chebby parts on a Mopar.

Do you have a part number handy to use Jeep calipers??? Most aftermarket kits use a GM metric caliper or a Ford calipers so if you have an alternative please enlighten us.

Gus

Yeah it's called get off your a** and test it out. Anyone can just pick a set out of a catalog. What happened to the pride? I have seen several set ups with mopar brand disc brake set ups. Yet everyone jumps on the chevy band wagon.

Billy if you have seen "several" setups then why can't you name one??? The guy you refer to as "THE MAN" offers his upgrade kits with GM and Ford calipers but he must not want to get off his "a**" either. The GM metric caliper has about a dozen different compounds depending on what type of racing you plan on doing so why would I want to put an inferior designed caliper on my race car? You "MOPAR OR NOCAR" types always make me laugh to myself putting second rate parts on your car out of some blind loyalty in a company that couldn't care less about you.
But this is America and we can all build our cars the way we want to
Good luck and I hope Fiat/Chrysler sends you a thank you letter for your blind faith in their engineering department
Gus

I just finished E-mailing Cass about a m/c for the 72 Duster.
I am going manual brakes with Wilwood discs on all 4 corners. He suggested using the 15/16" bore M/C.

I have a friend who used rear the caliper set up off of a Jeep Cherokee. I'll get ahold of him and have take pics.

Measure the master cyl bore you have on it now..
its just to large... you have a very hard pedal
and it moves very little distance.. correct...
put a smaller bore master on it
EDIT
here is some reading for you on ratios and masters
http://www.markwilliams.com/braketech.aspx

member FEETS has a good brake tech thread over on the "corners are best" section of the board to check out also.

I run a 7/8 bore Mopar cast iron unit on my street Dart, works well with Wilwood front discs, Ford Explorer discs on the back (oops, sorry I mentioned cross breeding) . The travel is a touch more than I like, but is stops very well with little effort.

Chevy bandwagon stops my car just fine! My pride is when I see the win light.

But we are not talking modern age cars. We are talking about cars that were built in an era of pride and affordability. I know growing up and racing where I live, a Chevy guy would pass you up on the side of the road if you were broke down just because you had a Mopar. Just full of alot mpre vintage pride and history. Just my two cents

Take a look at a K car master cyl.

http://www.rockauto.com/catalog/moreinfo.php?pk=1614196&cc=1069118&jnid=521&jpid=3

That's what my Dart had on it, the car felt like it would just sit down when I got on the brakes. I wish I'd looked for a kit and just rebuilt it.

But we are not talking modern age cars. We are talking about cars that were built in an era of pride and affordability. I know growing up and racing where I live, a Chevy guy would pass you up on the side of the road if you were broke down just because you had a Mopar. Just full of alot mpre vintage pride and history. Just my two cents [/quote]

We are talking hydraulics here.. nothing more..
if you can find/buy a cheaper caliper and make it
work whats wrong with that... all this is, is bore
and ratio stuff for a certain size caliper bore...
its simple hydraulics