Hoping the forum might be able to provide some leads on this - it appears as though all the standard part store chains in my area have either discontinued or are out of stock (with no restock date) on manual brake master cylinders to fit a '73/'75 Cutlass (it has the 15/16" / .938" bore vs. 1 - 1/8" / 1.125" bore used on cars with power brakes) I thought O'Reilly's or even Rock Auto might be possibilities - but no luck with either of those either. (For reference, I was ideally looking for a "RAYBESTOS MC39946" - but currently open to equivalent alternates?)
Any insight on a source(s) would be appreciated!
Thank you.

 

As an update - I am not positive on the 15/16" bore - as I have found conflicting info indicating it may be a 1" bore - but in either case, it would need the deeper manual brake rod pocket over the larger bore / shallow pocket 1-1/8" power brake master cylinders. Any leads would be appreciated!
Thank you!

 

Olds typically used 1" bore for manual disc brake M/Cs. The M/C for the 1970-72 cars with manual disc should work for you.

 

Joe - thank you for the info! Will be great if one from a '70-'72 manual disc brake car will bolt up! Will have to start exploring that as an alternate!
Thank you!
Todd