[Keith True]

These jack stands were made 60+years ago from a plan in popular mechanics.I know they've only been used as storage stands since the late 60's,and are in use today for that.Still holding up the same truck it held up back then,trying to keep from flat spotting the same new tires that were put on back then.I don't think I would be concerned about using a piece of good hardwood to wedge a jack,as long as it is trigged good it isn't going anywhere.