I tow now with a load-equalizing hitch and it takes any sway right out. Our new 20' 14K lb. trailer is a bit tongue-heavy unloaded and the new hitch makes all the difference. No more towing with my Dad's F-150 though, I'll be using an '86 Mack Ms-250P Midliner that gets over 20MPG and can pull whatever I can load. If it's bigger than that I finally got a 50-ton lowboy for our vintage '70 IHC Transtar!
So what did you find about the 6.2 that's giving you second thoughts? The only significant issue I've found thus far is that you need to keep an eye on the harmonic balancer, but other than that it's got a fantastic track record.