I believe maybe your right on the clogging but the knock is not random it very deliberate sounding and you can feal the vibration from it so....maybe converter on that one?
I'll pull the cat tommorrow,any other simple test I can do to eliminate some possible other causes?

 

When this happened to me i was on the highway going to a basball game, when it happened i knew exactly what it was. So i turned OD off and gradually got it up to speed and because the OD was off it eventually blew it out at highway speed beacause of the high rpm's, i then got it replaced the next day with a high-flow one.

 

Didn't get a chance to work on it today but for sure tommorrow I'm pullin it and draining the transmision and oil just to check for shavings or any signs of abuse. Couldn't hurt it either way.
Thanks.

 

Alright theres no shavings in the fluids and upon further inspection I think I'll bow down. Ramdamit may be right the sound maybe the cat. I'm gonna go get me sawzalll and see. Matter of fact I think your all right it's the cat.
Thanks for the help.

 

I know when my cat was on it's way out I was able to just give it a good smack with my hand and you could hear all the crap rattling around inside.

here's a thread on the dodge cat's you might want to read

https://dodgeforum.com/m_352822/tm.htm

 

Yep it just the cat. sawed it off and everything is fine...well except the 360 with open headers. So tommorrow I'll call the stealership as yall call it and threaten em for a replacement.Have an imaganery beer on me and a real one if I ever meat up with ya.If ya don't drink have a coke and a smile.
Thanks.