Just out of curiosity...what oil are you using? I remember reading a post about a service bulletin that indicated using Mobil 1 0w30 to quiet noisey lifters. If the oil passages were getting gunked up and starving lifters would it be possible it would be starving the number 1 cylinder? Maybe the use of Mobil One would give an once of protection. Has anyone blown a rod while using Mobil One to test this theory?