The engine that I am using weighs 216 lbs plus about 20 for shaft and prop. Its about 5 feet from the CG of the boat for 1200 ft lbs moment. A 9.9 Yamaha with bracket is about 140 lbs and would be 12 ft from the CG for 1680 ft.lbs. This means that if the boat was in the water without the engine and you set the engine into it it would trim 1.5 times as much by the stern from the outboard than from the diesel, though it would sink a small amount more overall with the diesel(a few hundredths of an inch)
For equivelent range under power the Yamaha would need ~1.5 times as much fuel so the weights are even closer than I've stated.

Dave