I just have the 4.6 v8, but it worked well towing my 8' pastime with my ~2700lb sailboat/trailer over Blewitt Pass in Wa. I never felt like I didn't have enough power, nor too little brakes, nor too much sway. So far the only mods I've done are the Timbren's on the rear.
I'll probably swap those out for springs that have a higher capacity though. I tow without the camper on, and they are just too rough in those circumstances.
I mention the weight because most, if not all, campers weigh more than they claim. I think my Pastime is pretty close to advertised weight, but it still was a good 100 or so lbs more than it should have been when doing the math with their numbers. So i'd probably expect a 980 lb camper to really be more like 1100-1200 dry, then start adding in all the extra "crap" you want to take with you.
You'll be over for sure... just depends how much. As I noted, a lot of people on here have no problem overloading an SD/3/4/1T truck, but shoot bricks at the thought of overloading a 1/2 ton by even 20 lbs.
Later
C