I have a 07 F350 and pull a 3h with 8ft short wall LQ. so it's kinda medium sized. Mine will do the same thing, It wants to sorta jerk, not by loosing power but more like it's bouncing forward and back. I usually haul at speeds of 70 to 80 mph and even when I hauled a 17ft short wall 4H Bloomer to Florida it got into the bouncing forward and back motion. The only way I could get it to stop is to let off the peddal for a second then I could get back into it and it would be fine. It usually does this around the same speeds your seeing. Not to much at slower or faster speeds. But again I've pulled two different trailers and seen the same thing soo I know it's the truck.

   I was thinking it might be the long bed 4dr with 4wd that gets the truck out of balance for a second until you let off and then speed back up after it stops bouncing.

   But one thing I do love about it is how well it pulls, I hauled the big a$$ bloomer to Jacksonville running 85 and 90 mph the whole way on the interstate. It has plenty of power..


    As far as the 08 radiators, I've heard the same thing. They are busting radiators at the mounts from the tourque of pulling heavy loads left and right. One rancher I talked to has 3 of these trucks and every one has had at least 3 radiators put in them already.

 I have a 2005  f350 did the same thing under acceleration I thought the wheels was square on the trailer.  took to the ford store 3 times they could get it to repete  when they come with the hooker to get it they found it was the fuel control module good luck 99% of the people that work on them have no idea what they are doing I ask 3 times to have my cluch fan changed because it blew hot air out of the ac when I was stopped for a light. They said they couldnt make it get hott I stopped the fan with a broom handel cause it wasnt working right then they changed it.