Best Plugs to Run with Shorty Headers?

[BMiller85]

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.

Same, almost need to just go to an auto parts store and compare em.

REALLY wish I could just use the regular AC Delco's. I talked to my guy and he said they're all gapped to .35 as they were from the factory, so very well could be it.

 

[BMiller85]

Picked up some NGK Copper's as research showed that their length post head were dang close to the Accel's, should be installed this week. Will report back, fingers crossed!

 

[Schurkey]

I'd be looking at scan tool data before I blamed reasonably-new spark plugs. Also looking for burnt plug wires toasted by the header tubes.

Ancient spark plugs might be a different story.

Kinda concerned about the lack of EGR also, 'cause there's no mention of disabling EGR in the computer programming. Removing the EGR plumbing was probably not a good move.

 

[BMiller85]

I'd be looking at scan tool data before I blamed reasonably-new spark plugs. Also looking for burnt plug wires toasted by the header tubes.

Ancient spark plugs might be a different story.

Kinda concerned about the lack of EGR also, 'cause there's no mention of disabling EGR in the computer programming. Removing the EGR plumbing was probably not a good move.

EGR was tuned out via HP Tuners.

 

[BMiller85]

Wanted to update for anyone that may run into this in the future. Purchased a set of NGK plugs, ref# 3951 and it fixed my issue. I went with the NGK's b/c they stuck out less from the block than most others, including AC Delco's.

It is worth noting, the headers had to come off the truck and dimple the rear tubes for clearance.

https://www.ngk.com/ngk-3951-tr55-v-power-spark-plug