i dont think its stock but its very mild..just messing around with the plugs the other day and noticed when i pulled them all most of them were gapped around .30-.45 nothing was the correct gap. also the plugs on the passenger side were all very loose ( came out by hand) and on the driver side so tight i busted two. could this cause a knocking sound?..but back to my point when replacing the cam its recommended that i replace the lifters as well right?