So I am going to be buying a new boat soon and I am not sure if ill be over the rating but my Ranger is a 2x4 3.0 w/ 4.10 gears. It is rated for 2360 but the 4.0 is rated for somewhere around 5860.. My question is will I still be able to tow more then 2360, I wouldn't tow as much as the 4.0 is rated for but since the trucks basically identical except the engine, could I get away with more then what the 3.0 is rated for? It would basically be for driving a little in the city to get to the highway then driving down the highway to the lake. I wouldn't mind having a slow acceleration either because as soon as I get up to highway speed I should be fine. Do you guys think this will be okay? Also I have no clue what the boat will weigh but it'll be a 16-17ft so it probably will weigh no more then 3500lbs. Also I might add that all the driving will be on a flat highway with not hills and no stops on the way to the lake.

 

I go by my owner's manual. If you don't have one your Ford dealer will have info where your truck is new enough. I would not exceed tow limits even with helper springs or other aids because the issue is not just how much the truck will pull, but how much it can stop, and how it can handle in an emergency maneuver. brake controller or not, if you exceed the towing capacity of your vehicle and are in an accident, there may be trouble when they find out you could not properly control your vehicle because you exceeded what you were supposed to be towing.
Mine is a 4x4 and weighs about 4000# alone, with the stuff I usually carry in the back. My gross combined vehicle weight rating is 8000# but driving with that much, and I have, is not pleasant. Flat smooth roads help, but be conscious how your weight, load, balance, and such. I was living out of my travel trailer attached to the back of my Ranger, so have some experience with towing.

If the trailer tongue is too heavy it makes the front wheels lift off the ground some. Bad for steering and for tires. If the back end of the trailer weighs too much it lightens the front but causes sway. The load needs to be balanced and the tongue weighs what it weighs. A weight distributing hitch spreads the weight between the front and rear axles but costs more and you still should not exceed GCVWR.

I am sure others will tell stories of having hauled a full 7000# mobile home 400 miles down the highway with no problem but I would not have done it for safety reasons. Your motor will pull more than your truck safely can.

My trailer weighs ~2500# fully loaded. A little less but I figure that for safety. At 6500 I am well below the 8000# GCVWR and it is comfortable. I know you are towing with a destination and won't be leaving it on there but keep in mind the things about tongue weight, load balance, liability, safety. I would imagine you would be rated at at least 8000# GCVWR and probably 3500# on the trailer, though that may be with a weight distributing hitch. What does your owner's manual say?

 

My father and I launched his 22 foot power boat with a 305 in it with his 94 3 liter Toyota. Hauled it about 35 miles or so on hilly, twisty shore roads with no issues. Remember to give yourself lots of room for stopping.

 

Just found this if it helps...

TRS Magazine - Towing Trailers