Hey gang, its been long but I finally finished my engine swap. Talk about bad ***. But anywho my 5.3 I had in my avalanche had a chatter when going up hills @ moderate speed and wen I was on the highway it made dat sound also I had only used the best stuff out therd from oil, spark plugs, which btw I went back to the iridiums and 92 octane. And changed my 2 knocksensors..Now that engine resides in my daughters 06calorado and still makes those noise. Any clue to where I look next?