master cylinder casting number help

Hi guys,
The MC on my 69 Dart has a casting number of either 2223541 or 2225341. I can't see it clearly enough. LOL Casting date is X3440. What does that mean?
Anyway, I BELIEVE this is a stock MC for a 69 Dart with SBP disc brakes. I have LBP discs from a 73 Dart on my car. Will this MC work for the LBP discs? Will I need the porportioning valve from the LBP car too, or can I use the stock valve from the 69??

Thanks for any help. I cannot find any info on these casting numbers from Google. You guys have done this swap a million times, this is my first one! I guess I'm a "Brake Swap Virgin"! :toothy10:

George