I have a 86 Grand prix with 305 v8 and I am going to replace my spark plugs. I went to autozone to get the plugs and they gave me ac delco r43ts spark plugs, but when i was looking through the haynes repair manual it says to replace with r45ts spark plugs. Which should I use?
ac delco r45ts spark plugs or r43ts
Jan 11, 2005
4 Replies
The R-43TS spark plug supersedes the R-45TS.
There was a TSB issued back in the mid 80s addressing the issue.
Basically it boils down to the R-43TS having the same cold fouling resistance as the R-45TS due to its copper core construction, the colder R-43TS reduces the tendency for spark knock which would be picked up by the knock sensor resulting in retarded ignition timing.
my old Chilton's book shows the 43 is for the V6, and the 45 is for the V8 engines GW
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shows R43TS, Rapid Fire 1 or 41-817 (platium) for your combo.
Thank for the info. I am going with the r43ts since i already bought them.
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