Read this before you swap...

I am not worried. I drive a 04 Ram with a 5.7 every day and have had no issues and my car is getting an 03 5.7.

The guy with the 300C....did he check his cooling system...20 miles would be just enough to overheat the thing again. Most of the issues involving valve seats on aluminum heads has to do with overheating the head. And this is not a new issue. If you overheat an LA engine you crack the head...same on most cast iron engines. Operator error or poor maintenance practices will kill an engine faster than anything. Sometimes you don't know you have an issue until its too late, unfortunately it happens but the majority of these engines are out there still kicking.

My vote as a driver/operator/owner is go late model 5.7/6.1 all day long and put the old stuff for sale for the resto guys!