Piston Identification help.

Picked up a 72 455 a while ago and was told that it was rebuilt, so i took it down to see what was inside (since the guy we got it from didnt know what was in it) and the pistons dont look like anything i have run before. The only numbers on them at all is the 60 on dish of them--nothing under the pistons or anything, I will include a couple pictures, any help with indentifing these would help.

Thanks

 

another one

second picture

 

and another

third

 

last one

last one

 

60 Over Standard Cast Pistons

Is my guess from the picts. Large skirt and a notch pointing to the front.