My 2002 4.2L has some slight piston slap when cold, nothing surprising, would like to try altering the spark timing to see if anything changes. I've just started using HPT and have only changed a small amount of TM and increased idle from 613 to 650 only to see if more oil flow would change anything. I suppose the change would need to compensate where the higher cold idle speed slows as the engine warms to a set ECT value, Would I need to change the hot idle spark as well as the warmup, that's where I'm not comfortable at tuning being a "rookie" to this. I'm watching as many videos and tutorials as i can. I will get a cold start/warmup log today.