1965 273 Head Gasket Question

Yep, no one makes 273 bore sized gaskets unless you have Cometic make some up. As far as the lack of holes or extra holes, I would be tempted to look at another gasket number to see if there is any difference. Check out Fel Pro 108 or Mr Gasket 1121G DODGE 4.5L/273 Mopar small block LA - head gasket KEYWORD - Free Shipping on Orders Over $99 at Summit Racing