This ones not mine either

[Swank]

See subject line.

https://tuscaloosa.craigslist.org/cto/d/1957-ford-4-door-312-v8/6519765590.html

[Hoosier Hurricane]

Another "it's a 312" ad.  Serial number beginning with B7 indicates a 272 was in this car when it left the factory.  Of course, it could have been changed over the years.   John

[SkylinerRon]

Wrong air cleaner & valve covers so who knows what else has been changed.

Ron.

[Lou]

If the car still has the original engine, the work needed to bring it back to factory stock doesn't appear to be too expensive, in my opinion the car seems to be a good buy. 

[Hoosier Hurricane]

I was not trying to sour the sale of this car.  I just wanted anyone on this forum who is interested to be careful to verify the engine if they are looking to buy a 312 powered Custom 300. It is a nice car.   John