Whomever replaced these before I went in put them in upside down.

What would the result of this have been?

Can this cause future issues?

 

if you have the heads milled they should be fine.

 

There are two mounting dowels at the bottom of the gasket.
I don't think there is an upside down.

Flip it over it is the same

Look at this head gasket here.

2001 Land Rover Discovery II Replace Head Gasket | Flickr - Photo Sharing!

 

The side that said "TOP" was faced down.

 

don't think it matters.
As long as the oil supply hole is not covered.
What does the gasket know or care?

May involve the crown seals for the cylinders being on one side of the gasket or the other.

SO, I stand corrected.
There may be an UP and a down even though the gasket is symmetric otherwise.