It's simple wood project, and very sturdy and easy to make; 3/4" plywood base with 2"x10" rails and supports.
Then I went to a tool supply store and bought some 3" caster wheels rated for 350# each. I put the wheels on it so I can roll them around to move them when I need to.
You can always use the "base" with out the wheels for storing on a shelf or to transport in the back of a pick-up truck and keep them from tipping.
It uses the oil pan rail to support the engine. We bought one made of metal many years ago, but the company is no longer in business. So I took their concept of supporting on the oil pan rail and made it out of wood.
