I made it. You can buy similar things. But I really was not impressed with most of those designs.
If your garage has a strong enough beam a chain hoist makes putting engines on engine stands much easier.
I have set engine stand legs like the ones linked below on top of a engine stand cart linked below.
This does work to adjust the height of a engine easy and get the thing onto a stand with most legs. But it is a smaller engine thing as your talking about 500lbs so you could potentially tip the engine.
They do make a 1000lb one. But I have no experience with it. Measure your spacing on your legs to make sure it will work. But it could be an option.