Whats a cracked piston look like? **pics**

[filburn]

These piston pictures below are from my engine. I don’t know how the hell they got there. I don’t know if they are scratches or if they are cracks. Take a look and tell me what you guys think. These pistons are from a probe 347 stroker kit for a 302. They are forged aluminum flat top pistons for a engine that has been over bored .030" Also, the engine is all naturally aspired.
















I know that scratches on the walls can promote pre-detonation but I have never seen what a cracked or busted piston looks like. So where do pistons crack normally? Where are there week spots? If these are scratches should I worry about them?

Any help would be appreciated,

thanks, filburn

 

[7-UP BILL]

Get them magnafluxed at a machine shop to be sure

 

[mustangjoe87]

I second the magna-flux then you'll know before you destory your heads and block.