1986 f350 460.

I have a question about the gasket that goes between the adapter and the block.

My adapter points the filter toward the front and has outputs for oil cooler lines. It uses a hollow bolt to mount to the block.

What does the gasket look like that goes in between the adapter and block? My engine gasket kit included a large o ring that fits, but the old one looks more like something that would be on an oil filter. More flat with square edges but still circular.

I didnt know if it was just the o-ring smashed down over 26 years turns flat?

Is that all that goes on the assembly?