Do I have to completely drop the oil pan to remove the front engine case?

Bad oil leak at highway speeds - a quart in 75 miles at 70 mph, but very little around town. Have replaced all seals, so am ready
as last resort to replace front case gasket. Haynes sez to remove the oil pan
Can I just loosen the bolts, letting it drop a little, and get the case off?

thanks, Tom

already donaated $2 in wrong section.