I've been in the business for 90 years, definitely the fuel pump.

Where are you located

So what is the difference between bad differential noise and bad wheel bearing noise? Cuz one mechanic told me it's the wheel bearing and another mechanic told me it's differential. But the differential is immensely more expensive than the wheel bearing to fix

Sounds fine to me

Mine is like that. My tires look fine though. Very weird.

I have an 02' Blazer ZR2 4.3 & it makes a sound coming from I'm assuming the rear, i replaced the front bearing hubs. Almost sounds like a low power steering sound but gets louder the faster i go. It only makes the noise while moving front or reverse. So I'm assuming it's a rear bearing or something. Nothing leaking, no play on the rear wheels, drive shaft is tight to the rear end. Has me confused. It sounds just like if it's low on Power Steering Fluid but again, only does it when rolling. No noises on throttle up.

what year was this

Dose it slow it down