2000 LT 4WD Blazer grind noise on acceleration

Everytime I press the gas, I hear a grinding noise that sounds like it's behind the dashboard. I don't know if it's behind the dashboard or not, but that's what it sounds like to me. It doesn't grind when I have my car in park and press the gas, and it doesn't grind when I'm coasting, It's only when I push the gas and am moving over 20 mph or so. I had my dad push the gas with the car in park and noticed no grinding, but the engine kind of jumps up. I am in 2 wheel drive right now and the blazer just hit 110k miles. It does it whether I'm in 2 or 4 wheel drive. It's not an extreme grind either, I have to completely mute the music to notice it. Can anyone diagnose my problem and how much it will be?

It may be a broken motor mount.
With the hood up, engine running, Parking Brake set, left foot firmly on the brake and the transmission in Drive, gradually apply the throttle with your right foot while looking at the motor between the bottom of the hood and bottom of the windshield.
If the drivers side of the engine raises more than 1 inch, the driver's side motor mount is broken and needs to be replaced.
The fan might be tearing up the fan shroud, making the loud noise.

Correct me if I am wrong, but wouldn't the motor mount make kind of a knocking sound instead of a grind? And the fan runs at all times doesn't it? If so, I should be hearing the sound constantly rather than just accelerating.

Anyone else have any other diagnosis?

The motor mounts simply holds the engine in place in the chassis. When the driver's side mount breaks, it will allow the engine to rise vertically on the driver's side which also allows some vertical movement to all the engine parts such as the cooling fan. The cooling fan blades can then make contact with the plastic shroud which sort of encloses the fan...makes a noisey grinding noise too.

I'll look into it. Thanks.