So I will try and make this short. I have an 08 with a ton or bolt-on's. 2.6 upper, 15% lower, professionally ported M121, 14 injectors and intercooler, twin 340 fuel pumps, JLT intake, long tube headers with hi flow cats, axle back, Roush intercooler tank, and I'm sure a few other things I cant think of. Since adding the 15% lower I have been battling spark blowout. Not sure how accurate the factory boost gauge is but it pegs hard at 15 hitting the stop. As far as the plugs go I was running SP471 starting at .30 and going down to .24. I was still getting blowout. Just replaced with TR6 started at .28 and was a little worse. Took them to .24 and its much better but still get some. Question should I take them down a little more, maybe .22 or go with BR7EF??? Thanks in advance.