1998 deville, 2000 sls, 2006 CTS-V, 2001 STS, 2007 STS V8
does anyone know the heat range for the two plugs for the sevilles(and other models)....41-987 and 41-950......the 950's are for 1999 and below and the 987's are for 2000 and up..so , what changed? ..i think its the heat range. but im not sure , anyone have any idea?...I am asking this because i bought some 41-950s from auto zone because they didnt carry the 987's..and i am using them in my 2000 seville. everything seems to run fine. i just want to make sure.