Buzz from dashboard

On my 98 K1500 5.7L V8 I get a buzzing coming from the dash once the truck is warmed up. It's loudest between 50-60mph and disapears over 60. I know it's not the fuel pump, the pump is loud but constant. This noise does not matter if you are pushing on the gas or not. I checked for loose hoses? Any ideas? Thanks.

what kind of buzzing? like the chime buzzer? or more of a mechanical buzzing? When I think of buzzing sounds I tend to think of something electrical (like a solenoid or contactor coil)

I changed the spark plugs this weekend and I no longer hear it? Maybe I bumped something closed or something? Thanks for the help