What's the difference?

I've got a Sb pan gasket around here somewhere. Not sure which it's for either lol. Don't even remember where or why I got it.

A note about the "chrome". I'm really not a bling kind of guy. BUT, it would be sort of vintage, and it was cheap....which was the main reason I bought it.

Thanks for tha info guys. I'll track down this gasket and see which it's for, and go from there.