What is the most compatible engine to exchange?

I have a 2003 Dodge 1500 with a 3.7 V6 in it, that year is known to have an engine knocking in most of the pickups that year with that engine, it was when they put a modification to the engine, they only had that engine in for 2 years. To get a used one to put back in it's 2500 and we dont want to do that because of the history of problems just to put it in and have the same thing happen again....we are thinking of replacing with an engine of a different size, we had a suggestion of a 318. Is it compatible, what modifications would we have to make? Is there a more compatible engine without the history of problems?

Already existing engine without having to do a lot of modifications?