1988 C1500 Silverado, 5.7L with some go fast parts.
On my 88 C1500 5.7L, I was able to remove the oil pan without messing with the motor mounts and raising the engine. Just had to rotate the engine a little to get the counter weights out of the way. On a 4x4 you have to jack up the engine.Obviously the oil pan will have to be removed to replace the crank journals but is there enough clearance after lifting the engine to remove the oil pan given the fact that the oil pickup tube drops down into the sump?
Also, on your cooling system, you should remove the Knock Sensor on the right side of the block and the drain plug on the left. There's usually a bunch of gunk still in there, you'll have to take a coat hanger and stick it in the drain holes to break up the stuff in there.