Danford,
It is fine to review the engine specs and have understanding of the engine performance. The low end torque figures are one of the shining features of the E-boost, however most often it is the real world figure that bites us.
In most cases the TV exceeds it max cargo spec or axle loading before it exceeds its towing capacity. You might say it can pull more than it can haul.
Here is the rig and the CAT scale information from my recent trip to the Ozarks so you can judge the suitability of a 2.7 E-Boost engine. I was loaded heavy for this trip.
My rig is
Tow Vehicle.
• 2011 F-150, 3.5 E-Boost, 4x4.
• GCWR 15,400 lb.
• Max TT weight 9800 lbs.
• Max cargo 1411 lbs. – factory spec.
• Max rear axle weight 3850. – factory spec.
Trailer
• 2010, 25 foot Dutchmen Lite
• 5000 lbs. dry – factory spec.
• Tongue weight dry 460 lbs. – factory spec.
This sound like a typical TV and TT combination and has pulled very well from Florida to the Rockies.
However a trip to the CAT scales shows some interesting details.
• The GCWR is 13,160 lbs. this is within the 3.5 E-boost limit.
• Loaded TT is about 6300 lbs.
• The rear axle weight was 3960 lbs, about 110 lbs. over the recommended limit.
• I calculated my max cargo at about 250 lbs. over the recommended limit.
So in my particular case I am already at or a bit over the TV weight capacity with satifactory performance, so I do not think I would opt for a smaller engine.
I believe the size of the TT you wish to buy will decide the suitability of the engine.
I hope this helps.