hey guys i have a 2001 5.3 silverado with the basic sts set up no cats and dyno tuned and i took it today for a few runs and at about 3rd gear (90 mph) i got .63 knock retard i was wonderin if any of u guys expiernce this or is it normal at that speed am runnin 6 psi and motor is stock just plugs gaped at .32

 

.63? I don't worry to much unles it hits over 2, but thats me!