Can small block oil pump be replaced without pulling the engine?

I loosen the dist cap and just tip it forward, then go tie a shop towel around the steering wheel to remind me to put it back on properly, before I try to fire it.
Some cars have interference, others not, I just automatically do it.
I also use a coupla bigger 1/2 drive sockets to space the motor mount biscuits up, you may need the 1 1/4 to turn the crank, but the counter weight holes work well with an extension stuck in, to rotate the crank.

Why are you replacing pump ?