Demco 21K autoslide height adjustment for a 3710 for a F-350

[Siriustoo]

Does anyone know which bolt holes (height adjustment) I should use for my new Demco Autoslide for a Montana 3710?
Heights are 15 1/4", 16 3/4" and 18 1/4".
Truck is a 2017 F-350 6.7 CC 4x4 SB FX4 Lariat with 18" tires

[cw3jason]

the 2017 sits high, try the bottom one, and see if it close to level and leave yourself at least 6 inches from the bottom of the trailer to the top of the bed rails of your truck for clearance.

[Siriustoo]

Here are a few pictures of the Demco Autoslide on my F-350 CC SB 4x4.
I went with the 16 3/4" mid setting. I suspect by the time we are connected the backend is going to be a lot lower.
Tonneau cover closes just fine.
Going to try this year with the F-350 SRW but I'm already thinking a F-450 may be in my future.