i have a 94 lt1 formula m6 with 120,000k. it is a DD. sorry i know its not an ls1. just trying to get a broader spectrum of opinion. i run premium and dont give it too much hell. I have a random knock that just started occuring after i changed my oil. it is on the right side of the engine. when i first heard it from inside the car i thought it was a rod, but when i got out and listened it sounded like it was on top. i took off the valve cover and let it run and made sure all of the rockers were tight and the push rods and lifters were ok(when i listened to it, it sounded like it was a top end prob.) its not a rythmic tic like a valve or consistent low knock like a rod. it is random and odd sounding, anyone have any ideas? thanks for any input.

 

I had a random odd tick with mine.. turned out to be a lifter. fortunatly I saved my oil and found some of the needle bearings... on an LS1.