Since the 1976 merger, there have been 35 NBA Finals contested.
By original playoff seeds, the Eastern Conference representative in the Finals has been:
#1 in 20/35 Finals (12 champions)
#2 in 8/35 (2 champions)
#3 in 4/35 (1 champion -- 04 DET)
#4 in 2/35 (1 champion -- 78 WAS)
#5 in 0/35
#6 in 0/35
#7 in 0/35
#8 in 1/35
By original playoff seeds, the Western Conference representative in the Finals has been:
#1 in 20/35 Finals (9 champions)
#2 in 5/35 (3 champions -- 05 SA, 01 LAL, 94 HOU)
#3 in 6/35 (3 champions -- 07 SA, 02 LAL)
#4 in 2/35
#5 in 0/35
#6 in 2/35 (1 champion -- 95 HOU)
#7 in 0/35
#8 in 0/35
If the question is how the teams with universal HCA has fared, the following #1 overall seeds have reached the Finals (champions in bold):
1979 WAS
1981 BOS
1983 PHI
1984 BOS
1985 BOS
1986 BOS
1987 LAL
1988 LAL
1989 DET
1992 CHI
1993 PNX
1996 CHI
1997 CHI
1998 UTH
1999 SA
2000 LAL
2003 SA
2008 BOS
The teams that had overall HCA but failed to reach the Finals were:
2011 CHI (lost ECF)
2010 CLE (lost ECSF)
2009 CLE (lost ECF)
2007 DAL (lost WCFR)
2006 DET (lost ECF)
2005 PNX (lost WCF)
2004 IND (lost ECF)
2002 SAC (lost WCF)
2001 SA (lost WCF)
1995 SA (lost WCF)
1994 SEA (lost WCFR)
1991 PRT (lost WCF)
1990 LAL (lost WCSF)
1982 BOS (lost ECF)
1980 BOS (lost ECF)
1978 PRT (lost WCSF)
1977 LAL (lost WCF)