What do you guys think?

Another thought! I can "slowly" cruise in 2nd @ about 15-1700 RPM before she shifts maybe into 3rd. Now I know you have 3:23 gears, however depending on your speed could she be down shifting on you when you let up on the gas. I know it's unlikely! but do you have a tach? When she holds back on you are your RPMs coming up?
PS I have (2) 8.75 sure-grips and there both kinda noisy "hummmm". Turn up the radio or louder pipes.