2001SS_stompinsupras

the car is a 2001 ss camaro 56,000 miles. catback exhaust,intake, you know the normal stuff. have problems with engine knock at high rpm, only in drag race situations. i'm hearing the knock only at WOT at about 5k rpm and up, but the condition is random, may not happen one run but the next it will. also i can race around town below 5k rpm with NO knock at all. and of course im running 93 octane. so whats up??

i have battle the problem before (52,000 miles) but fixed it with a pcv valve ,pcv catch can, and 2 bottles of GM top engine cleaner.solved the problem until now. DOES anyone have any good sugesstions? thanks