Power booster/ master cylinder ID tag help please

Hey guys,
I’m still trying to figure out what replacement booster/cylinder to buy for my 1976 dart. It has factory power brakes front disc and rear drum.
My research indicates changes between the 75/76 model years so it’s hard to determine my bore size and application for a factory replacement on front disc/rear drum.

If someone could help ID my tag on the power booster is greatly appreciate the help. It reads:
3580339
73608
300-5 A
C - 4220 B

thank you.