Where can I find a Master cylinder (for power brakes)?

[rxsuperhero]

I've checked a bunch of sites and a few parts stores and no luck.  Why is this part difficult to find?  I can find a Master Cylinder for manual brakes but, to my knowledge, it isn't the same.  Am I wrong? 

57 fairlane 500 V8 312

[Lou]

The bore on a power brake master Cylinder is 1/16 of an inch larger. I don't think using a standard master cylinder will make much difference, but check the bore size on a 52 to 58 Lincoln.

[rxsuperhero]

Thanks for the reply.  Found one on Ebay (of all places) for 70 clams.