I have may posted these photos many years ago.
This is the system I've used to carry my 13' canoe.
I don't carry it any more I now have a inflatable kayak.
The reason for no longer using the canoe is age.
Don't want to heart ourselves getting it off/on.
Younger age wasn't a problem.
The canoe has a roller wheel that rolls along the track.
There are stops in front that keep the canoe from shifting side to side.
Also on the rear roof rack are stops that do the same.
I use ratchet straps to hold the canoe in place.
There is a short chain up front that acts as a safety tie down.
My system has worked very well and with the 40# lifters the top goes up OK.