Older York Age Please

York gas pack

House built in 1957

serial #NMGM145763

Thank you

YORK HVAC DATING (Unitary Products since 1984)
Note: they skip the letters I, O, Q, U, Z.
Year of make indicated by 3rd letter in the serial number.

1971 - A 1992 - A
1972 - B 1993 - B
1973 - C 1994 - C
1974 - D 1995 - D
1975 - E 1996 - E
1976 - F 1997 - F
1977 - G 1998 - G
1978 - H 1999 - H
1979 - J 2000 - J
1980 - K 2001 - K
1981 - L 2002 - L
1982 – M 2003-M
1983 – N 2004-N
1984 – P 2005- P
1985 - R
1986 - S
1987 - T
1988 - V
1989 - W
1990 - X