I agree with you the power band moves but it seems like mine stayed the same. And the pump didn't seem to get louder. Maybe it is set at 20* but I sure expected to notice a difference. The get does seem a Lil cooler but not much maybe 50*.

 

Yes I have along with many others have made pretty good gains with timing changes. While I do not have dyno proof I do have extra footage and extra rpm turned at the end of a pull to prove extra power has been made.

Yes those are the symptoms of retarded timing going the other way should fix the issue. For advanced timing more plunger lift at TDC for retarded timing less plunger lift at TDC.

 

I will concede that pump timing can help facilitate making more power, but only to the extent that there are other mods which work better with bumped timing than without; and that the same timing on an otherwise stock truck would gain you nothing on the dyno, at least no more than you'd gain by driving from one dyno to another on the same day. 20° may not be enough to really hear it if you aren't listening for it, but it does start to knock with much over 19°. When you'll notice it is when there's a load on it that it can't do anything with, like stopped at a light in drive. Quite a few of my friends are running 25-30°, and those things sound like a rod is about to punch through when they're lugging.