Best Plugs to Run with Shorty Headers?

[BMiller85]

Hi all - Was hoping I could get some help on an issue I'm having. 1998 Silverado with a stock 5.7 Vortec V8. Wanted to get a better/more aggressive sound with the exhaust, so installed a Borla Pro-XS and a set of eBay shorty headers. In doing so, we had to remove/delete the EGR, which we did in via HP Tuners.

Given the tight clearance, my shop suggested that I purchase and run Accel header plugs due to their length. Upon getting the truck back post install, I am getting a little stumble when in park and drive (at a stop); I would estimate a 1-200 rpm drop.

The truck ran perfect before swapping to shorty headers. I do a lot of road tripping when my son to events so want the truck running 100%. My first thought is the plugs.

I've never had experience with Accel plugs, but know that AC Delco is what these trucks love most. My shop said I would be unable to run them given the length interfering with the header. Is there a model of AC Delco that is shorter/compatible with shorty headers? What are y'all that run headers running for plugs? Is there something else that I should be looking into outside of plugs?

Many thanks for the help/insight!

 

[PlayingWithTBI]

Is there a model of AC Delco that is shorter/compatible with shorty headers? What are y'all that run headers running for plugs? Is there something else that I should be looking into outside of plugs?

IDK if AC Delco makes one but, I'm running the Accel 416S gasket seat plugs in my aluminum heads with no issues (I have the Borla Pro XS too). For iron heads, you need Taper Seat plugs though.

 

[BMiller85]

IDK if AC Delco makes one but, I'm running the Accel 416S gasket seat plugs in my aluminum heads with no issues (I have the Borla Pro XS too). For iron heads, you need Taper Seat plugs though.

These are what I am running.

ACCEL 8198 ACCEL HP Copper Spark Plug - Shorty

ACCEL's patented race proven spark plugs in a Shorty configuration. The overall length has been reduced 3/16 in to 3/8 in (depending on the specific spark plug) to gain critical air gap between the spark plug boot and the exhaust manifold or header tube. This helps eliminate burning the spark...

www.holley.com

 

[Suburbarn]

The ones you listed are only 3/4 reach. If you still have Vortec heads, .700 reach is correct.

ACCEL P526S ACCEL Double Platinum Shorty Spark Plug

ACCEL's patented race proven spark plugs in a Shorty configuration. The overall length has been reduced 3/16 in to 3/8 in (depending on the specific spark plug) to gain critical air gap between the spark plug boot and the exhaust manifold or header tube. This helps eliminate burning the spark...

www.holley.com

Jeff

 

[BMiller85]

The ones you listed are only 3/4 reach. If you still have Vortec heads, .700 reach is correct.

ACCEL P526S ACCEL Double Platinum Shorty Spark Plug

ACCEL's patented race proven spark plugs in a Shorty configuration. The overall length has been reduced 3/16 in to 3/8 in (depending on the specific spark plug) to gain critical air gap between the spark plug boot and the exhaust manifold or header tube. This helps eliminate burning the spark...

www.holley.com

Jeff

I do, stock heads. Would you be able to point me in the right direction for which would be best?

 

[Suburbarn]

Acell PN P526S in my post above.
Unfortunately only available in double platinum for double the price!!

 

[BMiller85]

Acell PN P526S in my post above.
Unfortunately only available in double platinum for double the price!!

Apologies, I didn't see the link. Looks like these may fit?

ACCEL 8196 ACCEL HP Copper Spark Plug

ACCEL HP Spark Plugs are made with a Copper core which is a better conductor than Platinum and Iridium. They deliver a stronger spark especially in high performance applications where high combustion pressures are present. Copper is much better at dissipating heat than other materials which...

www.holley.com

 

[Suburbarn]

I don't believe those are the shorty version. They make regular length plugs too.

 

[BMiller85]

I don't believe those are the shorty version. They make regular length plugs too.

Was hoping to find an AC Delco that would fit the application, even if not "made" for the specific vehicle.

Side note- would the symptoms I'm running into be caused by improper plugs?

 

[Suburbarn]

It is certainly possible. The spark could be shrouded a bit from being recessed.
Could be the lack of EGR needs some supplemental tuning as well. I haven't run into that before. Two changes at once is not an ideal situation to diagnose. I would definitely take care of the spark plug reach issue first.

It could be difficult to find an AC plug that is short. I haven't seen any publications that list overall length.