273 intake runner size ? gaskets .
I have a set of 1965 273 heads and 4bbl Intake on the shelf out in the shop.
I just went out and measured the ports.
The port size on the Intake Manifold is 7/8" X 1 7/8".
The port size on the heads is 7/8" X 2".
The Fel-Pro Intake Manifold Set for 1965 is MS 9935 $11.62 @ Rockauto.com
The Fel-Pro Intake Manifold Set for 1966 - 1989 is MS 90009 $9.13 @ Rockauto.com
I beleive either set will work.
Herb