Yes, doesn't come from the cat, it's really engine related in my opinion. I'll try and see if i can get it on video

 

The sound appears to come from my harmonic balancer. It's lose on it's shaft. Is this a pressed or bolted piece?
Also probably better to not drive the car untill fixed i asume?

 

Likely the rubber has deteriorated, so the outer ring is just flopping around. Replace the balancer. Should be the end of it.

 

I'm looking into ordering a new one. It'll take up to 8 days till it's delivered with RockAuto! Hope i can drive it still for a 5miles a day to work and back.

Also i've seen there's different versions available.
OEM replacement by Dayco.
Racing versions by Dorman.
Street performance by Dayco.
And a Race performance one by Dayco
What's the big differences between these all? And OEM one will be good enough i asume my truck isn't tuned/modded.

Thanks in advance!

 

Just go with the OEM replacement. That's all you really need.