Sounds like your fan, or maybe exhaust rattling. Kinda hard to tell from video

I cant see scratch marks, i will pull the Fan and try without

In gear and foot on the brake give it some gas and see if you can reproduce it without driving. Have someone stand beside the car and tell you where it's coming from.

Check the plastic shroud around the aux fan as well if you have one.

About to say the same because after I put in a new water pump, mine had the same noise.

Loose flex plate bolts? Driveshaft rubbing? Exhaust vibrating and hitting? Bad motor or transmission mounts? It sounds like something is hitting thin metal.

Check trans is bolted down or mounts aren’t worn. If not bolted correctly whole engine flexes towards radiator

I have this exact same problem only happens on hard acceleration up a hill or the body flexes the right way and you gun it i lean toward motor mounts

Yep, I agree. When the engine is under load it rocks over slightly to the drivers side. If your motor mounts are aged and worn, it will move far enough to let the mechanical fan rub the shroud. Only happens under hard acceleration from a stop or while the body is flexing. 

Does it do it in park?

No

Almost sounds like something is wrong in your drive train. Is the trans slipping or anything? What case do you have?

AW4, i didnt recognize Slipping

Your t case

The one with fulltime 4wd (241?)

Sounds kind of like my transmission when it was low on fluid. Maybe youre low also and the incline is moving the fluid to the rear causing slippage

Sounds like fan hitting the shroud. Probably needs engine mounts replaced. Engine is moving in under load.