Doug, have you now eliminated the pinging? The intake/carb is all sealed up right, correct? In tuning, one always sets the timing curve first. Then you adjust the carb. I didnt re-read the whole post,. but I think you got that fixed. The Demon carbs are not junk. They can be very good at what they do. Like anything else, you need to understand how they work, and what might cause issues, to get them perfect. In many cases, out of the box they work better than what they replaced. That doesnt mean they are tuned, just better than before, and that's enough for a lot of buyers. If you're sensitive enough to see it's got an issue, then you can addres it by fixing the Demon, or finding someone who can for you, or replacing it with something else, and tuning that. I dont think you'll find any carb perfect out of the box. I never can. With your gearing and engine, I would run as first choice a Holley Street Avenger p/n 80770, it's a vaccum sec 770cfm (wet flowed) with electric choke. As a second choice, I dont think you can go wrong with a 4150 series 800CFM (dry flowed) double pumper. But the 800 will need tuning, as will the Avenger to get them dialed in.