Need Part # for aluminum master cylinder

I went down to my local part store (Lordco) and ordered a master cylinder for a 85 Dodge diplomat (that is what I read will work for this application) to use for the 11.75 inch disk brake swap on my 65 cuda. The master cylinder I received is not the aluminum one. Anyone can tell me a part number that my parts guy can cross reference? I know that Mopar Performance makes two different master cylinders one with a 15/16" bore size (P5249270) and one with a 1 1/32" bore size (P5249271) but those numbers don't cross reference to anything that Lordco carries. I'm trying to get a better price from my local part store(I have an account with them with a good discount).
I need the original Chrysler part # for the aluminum master cylinder, I believe they were on 79 and up cars and they had the larger bore size(1 1/32").
Thanks in advance!