^ PM sent my friendDid they swap pulleys ? I don't understand why the boost is different on those 2 pulls. I'm glad they got it right, but hopefully they will put the 2.87 pulley back in and get it tuned right.
The BOV fluttering is not a reason to change pulley's or back the tune off. If it was belt slip or something I could see that being a reason. Anyway it's what makes you happy is all that matters. 550 HP is alot and I'm going to enjoy that level for a while myself.
Also, once you cross that 600whp line you run into awhole another line of "weak points" usally in the drivetrain... rear diff, driveshaft, trans, etc... plus to even race the thing you need more safety mods..... rollcages, seats, bealts etc...lol, yeah traction becomes hard to come by once you cross that barrier.....we have a couple big HP shop car that blow the tires out from a 90+ stomp....its gets to the point where it isnt even streetable.