The standard jack for a standard LC works fine, and as Chris says, up it goes in no time, BUT, I have always had concerns over the small contact area at the top, located in the correctly shown picture on the jack under the axle. You could weld a piece of curved flat bar (sounds like a contradiction) across the top of a short piece of pipe to drop over top of standard jack to help position, or you could, - dare I say it on here, get a standard disco jack, it has `wings on top` to emulate the round of the axle. to stop sliding off.
Probably the one decent thing LR made !!
John