This looks like a great method. You could also use a motorcycle jack for the frame then just roll it over the motor.
At my work, they throw away bearing sliders and rails away that aren't all bad all of the time. If they get a little warn, they get tossed and replace, but would be great for something like this. The rails are either of two sizes, 1" or 1-3/4". I think the 1" would be strong enough. Then all I would have to do is mount some short hooks on both sides of the sliders where the straps would go, and you could just slide it in on the rail. And instead of using jack stands to suspend both ends, I could use my beam in the garage. When I built the garage, I was sure to put a overly large support beam in to hoist motors, snomobiles, what ever..... Great idea Bill!