Start with the easy thing first. This could simply be spark blow out since your still gapped far too large on your plugs for the set up. Try running down to 0.020 and see if the cut out is still present to eliminate that variable. And bonus if that's all it is. It could be! 0.30 is still too large a gap for FI on this motor typically. The more boost and fuel you have to run, the less gap you have to go with on stock ignition system.