I am pretty sure it is ignition noise. I've visited K0BG.com and listened to all the audio recordings. It is pretty much just like the ignition noise recording. I can record the noise and post it if you like. Here's what I am going to do. I've started isolating whatever it might be and taking notes for each thing I've done. I don't get the noise from the VHF/UHF side, just the HF side and it is from about 3 MHZ to about 28.00 MHZ. Seems that 6 meters is not very affected as I hear very little of this noise. I took your advice and listened for the sound under load. My noise seems to always increase with an increase in acceleration. It does not stop on idle downhill. It's there and its strong. I've disconnected coaxes from the radio and the noise stop. there is no noise with the VHF/UHF coax connected though. This noise only happens when the engine is running. I get absolutely no noise with the engine off or just with the ignition key turned to on or accessory positions.
I am still going to ground strap (bond) the tail pipe somehow yet and possibly ferrite core the coaxes at both ends and also he power cords. I probably will install a grounding strap between the hood and the firewall metal. Other than that, I am going to keep trying things. thanks so much for your input. I will continue to look at everyone's input until I figure this out. Once I do, of course I'll post all my notes for others that might have this problem in the future.
Are you sure it's ignition noise?
I currently own a 2007 GMC K1500HD that doesn't exhibit the problem. I owned a 1990 Chevy K1500 that made what sounded like ignition noise until I noticed that it changed not only with engine speed but also with load. Push the throttle harder climbing a hill and the rate increaed without an increase in RPMs. Release the throttle on a downhill and the noise stopped altogether. It turned out to be the fuel injectors generating back EMF from the injection pulse going through the injector solenoid winding.
Just something to consider.