Strange Grinding Sound

[SeventyOne]

To start I know this may be tough to help/diagnose over the internet but maybe we'll stumble onto an answer before I take my truck to a shop.

Like the title says I have a strange grinding/buzzing sound in my K5 that sounds like it's coming from the dash/behind the cluster. My initial thought was the speedo cable. Well just removed it and it's still making the sound.

It seems to come in intermittently, around 25-30mph while on the gas. Off the gas there's no sound. Also seems to increase in intensity as it approaches the trans shift point.

any ideas are welcome

[hemi43]

Is your Wife in the truck with you when this happens? ;-)

[SeventyOne]

Lol - i tried uninstalling the Wife from the vehicle but the noise persisted unfortunately.