The leveler makes a huge difference. Without it you will struggle and most likely chip/scratch your paint. And measure how far a reach your hoist has to the center of your engine bay without it hitting the nose of the car. Some of the hoists do not have much reach.
When I installed my motor, I made sure I could reach beyond the center of the bay. I had the back end of the car on dollies with the front tires on the ground. That raised the rear about 3 inches but it also allowed me to shove the rear of the car around if needed instead of trying to wrestle the motor, trans and hoist around for final alignment.
I also place a trans dolly or a car dolly under the car that the trans tail can rest on so as I insert the motor/trans, I can place the tail on the movable dolly instead of it gouging into the pavement. Saves the tail of the trans and replaces the 2nd set of hands to get the tail in place. The trans dolly has the added advantage of being able to lift the tail as it gets in place. Go slow and inch it in, then down, then in again. Too often everyone wants to rush and that is when mistakes happen or someone gets hurt!
A 2nd set of hands are a big help. But I remove/install my motors by myself (at 67 yrs old). Go slow and let the lift do the work. Make sure you test how the release valve works (how fast it will drop with the load) before you are over the car, Best to know before you have it over a fender or nose and when you go to release it to slowly lower the load and it drops! Scares the hell out of you at best!
Thom