I can try to answer whatever you give me. Let me do a little more thinking on the fuel problem and get back to you. Thanks for clearing those things up. As for the pinging. I've seen several things cause this. It seems to be worse on the trucks and tahoes around the 2000 modle year. There was a GM bulletin to replace the knock sensors and harness. They would corrode down in the bore of the sensors from getting water down in there. Water will run down in from the back. Mostly on vehicles that were pressure washed alot. Also they had you put rtv around the holes to make the water run around them. That is the only thing that gm has. Now i've had vehicles that got a fuel filter every 10k miles or they would start to ping. Also use a good filter. No cheep aftermarket stuff. Also getting rid of the platnum (100k) plugs and going to a coolder regular style plug will help. And the last thing is the fuel pump. Pressures will be fine but sometimes they just don't supply enough volume. Especially with mods. Some people push a lot of hp on the stock pump, but I have seen them cause this for the volume problem. Hoped I helped.