My 318 has a valve train noise. The engine was just rebuilt. Installed new Purple shaft cam. #5 intake valve train makes noise. I replaced lifter, pushrod and rocker arm. Checked oil port in lifter bore to see how much oil, if any, it was getting to lifter, checked ok. After engine is up to temp, the noise goes away. Im thinking worn lifter bore, which would mean no repair? Any other thoughts? Ill take any and all help on this one.