If I remember correctly, the ID of the holes of the intake and exhaust valve stem seals are different (exhaust > intake). You shoud be able to use that & figure out which ones go on the exhaust and which ones go on the intake.

__________________
1986 300E (3/2002) Rear ended and totaled (10/2009)
2000 Xterra (5/2000)
1992 400E (11/2009) -Sold
1986 300E (12/2009) - Sold
2004 E500 Wagon (6/2013) - Sold