Whipple originally supplied NGK LTR7-IX plugs with the 2018+ kits. That is what mine came with.

 

I just checked their website, and they still show that they sell NGK. It didn’t even occur to me until this moment, but I ordered the set from Whipple and the Densos are what the sent me both with the blower and when I reordered plugs. Hmmm.

I may touch base with them via email..

 

Quick update:

I reached out to Whipple about the Denso plugs and was told that they couldn't get the NGKs in the quantity they needed. Take that for what it's worth.

After comments here about Denso/NGK, I asked around. I ordered a set of NGKs that I will swap in at my next oil change. I will take some pics of the plugs in there for a 5k miles of e30 comparison to the original post.

 

Here is a plug after 10k miles since the first set of pictures. I ran a single tank of 93, the rest was all e30. Night and day as compared to the last set. The first set went 25k on all fuel types and this set went 10k almost all on e30. All I can see on these is a touch of pink at the top of the insulator, and I’m pretty sure that appeared after the single tank of e10/93.

The truck is about to go in for LTs, “green” cats, 1050xs, dual pumps, and a general once-over. I’ll have to do re-tunes then of course. I will probably leave the 91/93oct tunes as-is since I got a case of boostane prof to keep on hand for the times I can’t get E30, and hell, I can run straight e85 at that point.

One I get a new build finished (hopefully in the spring), I’ll pulley down to 3.5ish from the 3.75 I run now.