what are the advantages and disadvantages of 454 vs 350? I have a 454 in my beast, fuel milage is about 7-8mpg but it has a ton of power. With 4:56 gears and 33" tread it screamed at about 3500-3700 rpms going to Moab. I just put on 37s and it dropped to 2500 rpms- I can now drive it without ear plugs. aslo does the sound dampening paint help?