and you sure it's BPK8ES and not BPR8ES
for those that don't know bp - thread type and head
bk is a 16mm hex with 14mm thread
B is 14mm thread 20.9mm hex
p= projecting insulator type
r = resistor type
8 = heat range this is a hot plug (use in engine that have high combustion chamber temps can foul very easily at idle and low temps
e = is thread length (how much of the shaft is thread
s = electrode type (standard)