What aftermarket 4bbl intakes fit a 65 273

Yup. I had an Offenhauser Dual Port 360 on mine once upon a time. It worked quite well. You can hog out the bolt holes and make a later manifold fit but that's a pretty hillbilly fix. (I hate to admit it but I had this hillbilly fix on a car for a few years....)
Good luck in your search!