I think you will find that the difference between a 3/4T and a 1T is very
small in most lines. Look at the towing capacity ratings and the 1T
vehicles are usually rated less than their 3/4T equivalents. They have
the same engines, driveshafts, axles, frames. Just a heavier duty
transmission and rear springs. Frames are often the same in 3/4T and 1T
models.
If I was ordering a new van I would opt for a 3/4T unless I wanted a more
powerful engine that was not available in the 3/4T, or if I had to get
the 1T to get the long wheelbase. The 3/4T models seem to have a little
less rigid suspension for a smoother ride. Our former 3/4T Ford pickup
had a surprisingly mild ride for a heavy vehicle. and that's from one who
was spoiled by years of traveling in Citrokns.
Al