The truck is completely stock 2014 L83 5.3 Crew Cab 4x4 except for a On3 76/65 ball bearing turbo kit on 8 psi. I am currently running stock coils with ltr7xi plugs gaped to 25. The truck pulls hard under 4k rpm's then it starts to miss badly only on cylinder #8. I have tried the following: New MSD coil packs all 8 didn't change anything so I went back to stock coils. New plugs same ltr7's, new MSD wires, No boost or exhaust leaks anywhere, and I compression tested #8 it was 210 psi. I am at a loss could it be fuel related?? The truck runs perfect in normal driving conditions even above 4k RPMs it only starts to misfire when I am above 70% throttle. I attached a log I did the other day check out around 7:52:51 it misses so bad on #8 but around 7:55:45 mark it's making 580 lb:ft at 3,200 rpm's and pulls really hard and it's not missing. This is a new build and the truck didn't misfire under WOT when it was stock.