I'd put the wide part of the "fire ring" on the block.
Why? hell I don't know,
but a block has a chamfered edge and a head is flat.
so maybe the wider part would still seal good on a chamfered block.
I've seem gaskets installed both ways.
Some are very specific on orientation, others make no mention as either way is good.
Others can go only one way by design/ shape/holes.
look, thinking as I have said to see if there is a preferred choice.
also look at what you took off if factory installed, as there will be witness marks showing which way was up.
----Just some things to think about, and muddy the waters
