I've never moved a tank that large, but I did twice move both a 75 and a 55 without a problem. Yours is obviously going to be more difficult, but the same principles apply, imo.
What I did was heavily pad underneath the tanks, added pads / cardboard along the sides, then strapped (roped) them so they couldn't move in any direction inside the truck / van. This was inside a vehicle with other objects. (So it was good as we had more things to prop against and bad because we had more things that might move and strike the tanks.)
Heavy pads were comforters, blankets, and towels. Rubber mats or boxes, would have been ideal, but we didn't have those. Fluffy pillows were good for the sides.
Driving was slow with no sudden starts or stops, no train tracks and a lot of care on turns and steep grades. Iirc, we used emergency blinkers in a number of places.
The other issue was moving them into and out of the truck, through doorways, up and down stairs, etc. I had great help with that. That required a lot of patience and care.