[powerdyne 5.0]

Ok, first off I will tell you what i have on my car. pwerdyne s/c 9lb, headers, x-pipe, catback,24 lb injectors, pro m 75mm, tko, 3.55 gear , adjustable feul reg. stock motor. Now, her is my problem. When my i get on my car above 4750 rpm it seems to surge. I can feel my car try to go faster but it just kind of feels like i have bent rims, but there not. its hard to explane. Could my lifters be bad, leaky injector??? I really have no idea. I just know it happens at high rpm when i get on it?? Oh and my boost gauge only says 5-6 lbs of boost.