what bore master cylinder do i need?

[barracuda7199]

i am looking to swap an aluminum 2 bolt master cylinder on my 71 cuda. i have the adapter plate already the car was an original manual drum brake car. I swapped to 73 and up disc spindles with the 10.89 rotors and pin calipers. the rear brakes are 11" drums with new shoes and 7/8" wheel cylinders. i really wish i could have found some 12" rotor caliper adapters when i did this swap about 9 years ago...
what bore master cylinder do i need? i have a few on the shelf how do i measure them? with a dial caliper measure the inside where the pushrod goes?

[brads70]

I'd ask Cass aka DrDiff? He set me up with 1 1/32" bore M/C  for my combo?   

[barracuda7199]

How is your pedal effort? Is it like pushing on a brick wall?

[brads70]

How is your pedal effort? Is it like pushing on a brick wall?

You do have to push , but I am using manual brakes? I have most of the parts to convert to hydroboost, just haven't got around to it yet? HB uses a bigger M/C  1 1/8" I think Cass set me up with?

[barracuda7199]

well the master i had wouldn't work it wasn't machined for the pushrod retainer. so i got the same one as you brad from dr diff not a bad deal when you know what he has will work. i will just put the adapter i have now up for a later project.

[brads70]

well the master i had wouldn't work it wasn't machined for the pushrod retainer. so i got the same one as you brad from dr diff not a bad deal when you know what he has will work. i will just put the adapter i have now up for a later project.

 :2thumbs:ya Cass is a big help!

[barracuda7199]

a little follow up on the dr diff master cylinder. everything fit great the pedal effort feels good to me and the adapter plate was the right thickness so i could reuse my stock manual brake pushrod. anybody in the market for a new master cylinder should give cass a call or just buy from his ebay store great guy to deal with.