Hi, guys I am new to this forum, hope you all doing well

I have a question: Should I do a swap?

So me and my buddys are looking to grab this 1998 mustang convertiable its a 4.6L V8 automatic.
The person told us that its making a knocking sound. hes not sure why its making it but it is.
I just wondering what the cause could be, and if its worth fixing. the car has 164K km on it

If I were to swap it, would a 5L V8 work, also since I am swaping it might as well change the auto to a...

Should I do a swap?