Jjblur

Guys, just got the truck off the dyno. Totally rebuilt with lt4 bottom end, tsp lt1 stage 1 cam, 3.25 pulley, johnson lifters. 2.9 whipple. Truck made 500hp on the l86 with 3.75 pulley at 6200. Now its makibg 567 on 3.25 pulley. Kicker it makes it at 5200 and falls on its face. What could be the problem. It has factory airbox with whipple intake tube. Could that be the restriction? Tuner said it has plenty of fuel. 18 deg adv. 3 inch dual exhaust no cats thru a magnaflow