Brainstormin' 440 vs 5.9 ...

I don't know..... .050?? I can't even remember the part number, but I usually use Fel Pro. I had the calculations then of the original gasket and what I'm using now, that's how I came to the .030 mill.
Why? lol.
Get a steel shim in there, while you're in there measure, probably figure out to be 8.5: 1