Need help diagnosing a noise

[rwljpl]

Need help diagnosing a noise.

My truck has a GM crate 350 HO with a few thousand miles on it, a rebuilt NP 203, and a more recently rebuilt 700r4. I started getting a clicking/clapping sound but I’m not sure where it’s coming from. I’m guessing the transmission but I really don’t know. At first it only happened under load. Now I can sometimes hear it when I’m in park, but it really picks up under load when accelerating.

I’m going to try to post a few videos. Any help/insight/educated guesses would be appreciated. You can get the videos in this Google drive - 2 are from inside the cab under load, another is underneath obviously in park:

K10 - Google Drive

drive.google.com

 

[Camar068]

rigorously crank each drive shaft both ways. Feel free to push it up/down with force all around to check your joints.

 

[rwljpl]

Thanks- I thought it could be u joints too but I don’t think it is
The noise doesn’t seem to be coming from that area and I checked the joints and didn’t hear anything
The joints and drive shafts are pretty new
Other ideas?

 

[Originalthor]

I would check your flywheel torque converter bolts. I've seen them loosen up after a fresh install. Even check your trani bolts. I've even seen them come loose and make wierd noises.

 

[rwljpl]

Thanks
I’ll check into that

 

[SquareRoot]

Flexplate cracked or loose bolts like mentioned above.