Hi Dr G. J.
My instructions about the towing angle came from reputable dealership
selling utility tandem wheel trailers with a gross of over 7K pounds. The
angle is independent of the hitch weight. Towed without spring bars behind
my F250 super duty.
I use a Hensley towing my '74 Argosy 22, but it's most likely overkill. The
coupler is high due to the sagging Henchen axles!
Keep the comments coming, as I still have a lot to learn! :)
'74 Argosy, Joy