The stock 4 barrel manifold is a good one. I'd pass on a D4B and leave it to the 64 and 65 guys, they have very few choices. Besides the bolts are at a different angle. You can use anything, even stock 340 manifolds. Any 4 barrel manifold will beat the 2 barrel anything. Holley Street Dominator is small port good fuel distribution, Weiand manifolds look period and are good, Offenhouser are good if you run across one, Edelbrock Performer should be good. 273's love rpm and since yours is solid lifter, I'd skip low rpm manifolds like a Streetmaster or the Sp2P unless you are only interested is squeezing every drop of gasoline and are willing to forgo performance to do so.
Things to look for are stripped threads and poorly repaired threads, at bad angles, plus erosion in areas that come in contact with coolant, especially in aluminum. Also check sealing areas carb, port surface, , water, and exhaust.