2012 5.3 knock HELP

[Remingnton]

Hi I need some help here, I’ve got a 2012 GMC sierra SLE with 112,000 miles on the chassis had a knock develope about a month ago saw I had a cam lobe that was worn so ordered a new motor and put it in. While replacing the motor I went ahead and used all new hardware and put new knock sensors can sensor crank sensor oil pressure sensor new spark plugs and new motor mounts, started the truck after priming the oil pump ran great until warm than started with the knock again. It’s a bottom end knock and it’s very inconsistent. When the truck is flat on level ground there’s almost no knock. When on an elevated surface like a hill it sounds like there’s a monkey with a hammer inside. The comes from the rear of the motor around the bellhousing area and I’m just not sure where to go from here. I’ve tried a bunch of stuff and it’s I’m hesitant to say it’s a bad motor, it’s a brand new motor with the same knock that the old motor had. 

[CamGTP]

Probably have a cracked flex plate if I had to guess. A broken flex plate can cause a knock like that.