Don't worry about getting the tank higher than the engine---just worry about the oil level in the tank being higher than the pump!

A pump can(and does) lose its "prime"! So to keep the pump primed all the time, you mount the tank so the oil level is always above the pump.

Now for a true story---A friend had a nice dry sump installation----worked fine! This is until he put the car on an inclined trailer and pulled about 200 miles. Fried the engine on startup! Why? The pump was above the tank for the 200 mile trip and the pump would not suck oil on startup!

Opps!