My own dyno numbers, I just got today so I felt like hitting this thread again... Were 465 hp/447 with some nasty spark blow out myself. I also have NGK Iridiums gapped at .038 and saw spark blow out in the 5.5k and up RPM range.
I have similiar mods, 2.76 upper, stieg stage 4, throttle body/plenum, cai, hi-flow cat and catback exhaust.
Predator's really suck to tune with I have concluded, I have no idea what my spark advance is at since they only use percentage but don't tell you percentage of what.
The AFR from the dynojet said 11.0 but the wideband in my car disagreed and said 11.7 for most of the run. I stopped there and decided to take autometer's word for it and not the dynojets. I have an appointment with a real tuner in a week and a half PLUS asked for a tune from RWTD.
Anyone have any suggestions? Besides close up the gap... seems like my numbers are kind of low. I would expect at least 485hp out of the combo according to what people post on the internet.