I just looked at the Cl ad, looks like a LA small block, now it is your job to check out which one! Looks like it is a 2 barrel carb, but can't tell for sure. The Cuda is definitely a 67 - many people get the year wrong.
Easy. Just pull the valve cover and look for adjustable or non-adjustable rockers. All 67 273's had adjustable rockers, all 318's had non-adjustable rockers.