At around 2600 rpms my car has a knock. or what sounds like a knock. After you get past that area nothing. What is it?

 

hard to say get it scanned using autotap and see if theres any knock retard and then go from there

 

Yeah and figure it out before you spray it again!

 

Is this in any gear? Any temperature?
Have you noticed oil consumption?
What gas are you using?

 

Yeah at any gear. Yes there is some oil consumption, but isn't that normal when you rod it?

 

I'm assuming it's pinging. With our LS1s the cause (when using premium gas) is generally oil contamination of the mixture. Stop the oil consumption and you stop the pinging.
The most common cause of oil consumption is sucking it in through the PCV valve. The easiest fix is a 4 quarts of 10/30 and 2 quarts of 15/45 (or similar thick stuff).

This should stop oil consumption and if that's the reason for the pinging, it will also go away.