I didn't really closely inspect the bars that I saw, but they did look larger and stronger than the old ones. I looked at the online part catalog and it looks like the new part number is LVA15836. The picture is line art and doesn't show much detail. The older flat bars were also shown with a note of "NLA" which I assume means "No Longer Available." If that is true, you should get the newer ones. Here is a link to the parts catalog:
Featured Agricultural Parts
Choose "View parts catalog" from the lower left menu.
Featured Agricultural Parts
Choose "View parts catalog" from the lower left menu.