AC Delco Plugs
Thread Starter
Intermediate
Joined: Aug 2019
Posts: 48
Likes: 8
AC Delco Plugs
Hi guys, I’ve been looking at past posts, but I’m not sure about correct plugs for my 90 L98.
I see the AC Delco Rapid Fire seem to be the consensus. However I’m looking on Summit and I have several choices. I don’t see FR5LS ?
Summit offers #19307139, #103908030, plus several others. I’m sure the aluminum heads recommend a specific plug as well.
Advice please!
I see the AC Delco Rapid Fire seem to be the consensus. However I’m looking on Summit and I have several choices. I don’t see FR5LS ?
Summit offers #19307139, #103908030, plus several others. I’m sure the aluminum heads recommend a specific plug as well.
Advice please!
Melting Slicks
Joined: Mar 2002
Posts: 2,874
Likes: 764
From: Sligo PA
I wouldn't go with ACDelco plugs. I would use NGK FR4 if it's stock. If you have a built motor with higher compression and aluminum heads I would go one heat range lower so a FR5. If you are running boost or nitrous I would go with 2 heat ranges lower and a lower non-protruding ground strap type plug.
Racer
Joined: Jun 2006
Posts: 384
Likes: 62
From: Chicago Illinois
Hi there:
I know the purists on here may blast me for trying a "gimic" in their minds, but I decided to try a set of E3 plugs in my 1989 convertible. I have no experience with them, but for about the same price as the factory correct double platinum AC Delcos that were not available at my parts store without special order, I got the E3s installed a few days ago and will post some mileage and seat of the pants dyno results after I put some miles on them.
I have never used Rockauto for parts so I cannot comment on that auto parts company.
Good luck.
Ted
I know the purists on here may blast me for trying a "gimic" in their minds, but I decided to try a set of E3 plugs in my 1989 convertible. I have no experience with them, but for about the same price as the factory correct double platinum AC Delcos that were not available at my parts store without special order, I got the E3s installed a few days ago and will post some mileage and seat of the pants dyno results after I put some miles on them.
I have never used Rockauto for parts so I cannot comment on that auto parts company.
Good luck.
Ted
Melting Slicks
Joined: Mar 2002
Posts: 2,874
Likes: 764
From: Sligo PA
I like AC Delco parts for things like wheel bearings and tie rod ends. But in plugs NGK's are just a better part. The price about the same and they last longer. They also tend to be in stock at most auto parts stores. I guess it might be brand preference also. I will say this though... NGK plugs put up with way more abuse with nitrous and in 2 stroke engines than AC Delco. But YMMV.
