Mopar Rookie Question

I have 2 small neck AFB, 400 cfm that came off a 1962
413 dual quad 385 hp
Ahhhhhh, there ya go! I did so hoped to see Federal Mougal or Edelbrock make 400 cfm carbs, but the 500 is as small as they got. Getting those original carbs is a bear to find for starters and expensive when you do find them. Normally for what I see at least.