Excellent towing vehicles, we pull our combined trailer/RV with our 1999 D2 V8 and it's great:-
It goes 3.5 tons with the engine in the back.
First picture is the rig at Hook of Holland ferry port, returning to the UK after its first trip to Nuenen, second trip is this year, a rather wet rally field. Show was good though.
They are sensitive to tyre pressures when towing standard trailers/caravans, and the way the trailer is loaded makes a difference. Always make sure that the load is forward on the trailer and not too far back.
The centre of gravity of the load also makes a difference generally, we pulled a Series III 109" 6-cylinder back a while ago, that was on a relatively high trailer and we did have swaying problems until we pumped the trailer tyres up.
Similarly with our oldest boy's Defender CSW, once we had the trailer tyres pumped up and the vehicle well forward on the trailer, it was no bother.
Towing the engine on the older 4-wheel trailer, just over 2 tons all-up trailer weight.
Our youngest son's Series III with 2.5 n/s diesel and his Sankey trailer loaded with engines.
Load it properly and you'll have no issues. We run at 60mph on the motorways with no problems.
Peter