Just pulled the head off a 455 I picked up recently to see whats inside and condition. Motor is super clean inside. no gunk.
Let me know if you can ID this piston. The cylinder measures 30 over.
Thanks

 

Hard to tell for sure but it sort of looks like it is a forged piston. Do you have the pan off ? See if you can see any numbers on the underside of the piston. Get the rest of the carbon off one of them and see if there is any numbers out near the od.

 

no numbers on the top surface. they all cleaned right up nicely. I'll get the oil pan off in the next day or two and have a look below.
I saw a one on summit's website called a step piston.

 

D shaped dish. I don't know which manufacutrers make those.

 

If it is actually a step dish then it is probably the KB. They are the only ones I know of that do that type of piston.