Coil Confusion

I have it mounted horizontally on the Edelbrock intake, just behind the carb.
If all the numbers on the coil are good, could it just be a matter of moving the coil off the intake on mounting it verticle? That easy?

BTW, I have the coil sitting next to me and when I shake it, I hear the oil. I guess that means I have not cooked it all out?

If I bought a duralast gold coil as a backup, it should just be "plug and play" just like the MSD, correct?