Bbc fuel pump identification

[madden]

hi

need help ID. this fuel pump

i have a box full of these.............i believe they are bbc AC delco mechanical fuel pumps
some have ac on the bottom and others dont

got them from a gm dealership and was told they were 396/427 hp ????

any help with ID and valve of what they are worth would be great

thanks so very much

regards
chris