What carb is this??

I think they call that one the BBD but I'm not positive. It probably says on the side. The 2 barrel 318 carb is the same carb. It flows the same ammount of air. It won't gain you any performance if that's what your after. The only 2 barrel carb that was bigger was used on a 360 and it had a larger bolt pattern so you'd need a 360 intake also but it don't stop there because the runners were also larger so you'd also need 360 heads. If your looking to improve performance get a small port 4 barrel intake such as a Edelbrock performer and small 4 barrel carb like 600 Holley or Edelbrock.