I have a 1999 K2500 with a vortec 454 in it. I got a tuned ecm from black ear performance and I had a question about timing. When it’s cold it idles at 30 degrees adavanced and when it’s warm 27ish adavanced. My question is, is timing supposed to retard when I press the accelerator. During highway driving when I gas it but don’t downshift it’ll retard to as much as 18 degrees and from what I know isn’t my base timing supposed to be lower and then it advance with acceleration?