This problem started off as just a slight whirring (like a low power steering pump) but is getting louder now. It's a slight roar and gets a bit cyclic at 65mph. It happens in 2wd or 4wd the same amount.

Wheel bearings, axles?

I can replace them, but I am not very good at analyzing. Thanks for any help you can give me.

 

start here. jack the truck up with the front tires completly off the ground. grab the tires at 12oclock and 6oclock. try to rock the tire from top to bottom if there is any movement it would be the axle assembly
your problem sounds like what just happened to my 2500hd
good luck.

 

It was a wheel bearing, no play in it at all, but it did have a slight clicking noise coming from it when turning the wheel.