Wind noise inside my cab is really annoying me!

[MDeCook]

Hi all! I knew my truck was going to be loud when I bought it. Thats actually why I bought it! For some reason though my truck is developing a very annoying wind noise above 45 mph. At 55 you can drown it out with the radio but at 70 mph you can hear it over the scotty II intake. I have the hole cut in the cowel for the scotty but it did it with the stock intake too. Its kind of like riding in a wind tunnel. It seems to be coming from the center dash/trans cowel area. I did notice the insulation on my fire wall has come loose and was wondering if the wind could be getting in between the loose insulation and the fire wall creating the noise. I did a search on sound proofing but no one ever mentioned a wind noise. Just the usual clatter/music coming from the cummins. My questions are,
1. have any of you had the insulation on the fire wall come unglued thus making the cab louder/windier sounding?
2. would it hurt anything if I took the insulation off the firewall? If I did this I planed on adding sound proofing to the inside of the cab but I wasn't sure if the fire wall would get to hot and pose a hazard with no insulation on it?

My first attempt to fix this was to fit a piece of tin around the shift tower Under the rubber boot and seal it with silicone. That made no difference.
If I could get rid of the wind noise I really don't care if its any quieter. Any ideas or suggestions would be appreciated! Mike