I only have a '65 parts book, and it shows the left as 2465845 with a note "w/Heat Shields"; Right is 2465842. no illustration shown for either. So, the photo of the NOS gaskets you posted in #8 matches the original shown in my post #9. I believe the gaskets shown in #8 are the original factory installed configuration for '65 which DOES have a left side web. The gasket/heat shield shown in #2, #6 and #22 do not have the web and are later cars. I think they dropped the web for '66 and newer, and it became the replacement for previous as well as later 273s. Another possibility is that both were used concurrently, but at different assembly plants.
