Opines or facts please

The plastic one requires a thin paper gasket on either side.

The really cool one to fine is the spread bore Chevy heat plate that was used on a spread bore Holley in like 69 camaros I believe. It was aluminum with stapled gaskets on either side (fits thermoquads) and has the firing order stamped in front.
I had a few years ago for all my thermoquads when you could buy the the part new from Chevrolet.