I'll try anyone who may be able to assist. How do I contact this Evan Williams?

Is this car on e85?

Try the liquor store you were at earlier.

93

You need to change the title of this thread to "Old High Boost/Load Sputter"

I wonder if this could be fuel injector related? As in, there's sufficient fuel being sent from the pink, but the injector(s) isn't opening at the correct time? Is that a thing?

In case anyone's still listening, here are two back to back logs. The first was at 17psi and had (essentially) NO stutter issues. The second was at 21psi had immediately started stuttering/running rough starting at around 5K and 5.5K RPMs. It stayed rough through the remainder of the pull.

AFR and Boost are solid for both pulls so you'd really think it's spark related.

So after all those parts and changes, here is what resolved the issue: Bringing the spark plug gap from about .028 inch down to .018 inch.

Previously I had never touched plug gap, so how it suddenly became an issue is completely beyond me. It makes no sense but I'm not complaining I suppose.

Thanks again for everyone's feedback.

Way to late but yeah, trying a smaller gap should have been the very first thing you tried. Iridium plugs with a small gap is what I have to run to make it spark reliably. I think I'm at .016 or .018, something tiny. Used to be able to run more as well... I think the coils just aren't performing as they used to when new.