Here's an example that's somewhat similar to the commercial unit sold by Atlee Dodge - http://www.fadodge.com/wing-jack/
In addition to the welded attach brackets I've seen them employ square bend U-bolts and straps across the threaded end bolted to the jack upright holes.
Gary
In addition to the welded attach brackets I've seen them employ square bend U-bolts and straps across the threaded end bolted to the jack upright holes.
Gary