To Hank and Terry and anyone else that has used the specific fire bricks mentioned in the original post:
When researching, I found that there seem to be two types of what people commonly call "fire bricks".
The first kind have an insulative property. in other words, you can place them next to a fire and they will try to remain cool to the opposite side. These might line a residential fireplace or the outside of an outdoor fire place. The other type is a conductive brick, which is intended to absorb and retain heat. These are what you would line the interior and especially the bottom baking surface of a pizza oven so that the crust gets done.
For my purposes, I would prefer the former - a brick that does not conduct or radiate heat to the opposite side. Long story short, is that the type of bricks in the OP?.