It depends on the stand. Several years ago a couple of students in the school auto shop where I teach were rebuilding a 235, and they had removed it from the stand, mounted the flywheel, clutch, and bellhousing, and re-mounted it on the same stand. The next day, the engine, with stand attached tipped forward and hit a kid's foot on the way down. It broke a few bones and took 13 stitches to close up the cuts it caused. He was wearing heavy work shoes, not steel toes, but heavy leather, which prevented more serious injuries, or possibly losing some toes.
If you choose to mount the engine that way, you'll need to fabricate some type of front support unless you've got a stand that's purpose-built for an I-6 engine.
Jerry
