Is there any way to drop the oil pan down far enough to install all the gaskets without raising the motor?

 

no

I did it in my c-10 by removing the first main cap

there was just enough room in the truck

so let me just say "no"

 

so to put the seal that goes under the timing cover ill have to lift the engine and drop the pan

 

I just did this last month... jack the engine up from the pan.. and let it rest on the motor mount bolts.. you might have to turn the engine by hand if the counter weights get in the way.. thats the simplest way of doing that w/o taking the whole engine out of the car.