You snapped all the heads of the intake valves, and thats the only damage to the pistons??

You got really lucky then!

Check the guides for cracks.

 

Same thing happened to me except I have oem pistons (are yours oem?) and it only happened at startup...not under a load or at freeway speeds....pulled the head, did a complete timing job, got a head job with new stainless steel exhaust valves (only the exhaust valves kissed my pistons) and slapped her back on...DONE.

I will say I had NO marks on my piston tops....unlike you.

Runs almost like new again after this and I have 155,XXX miles....this just happened and I have less than 1000 on rebuilt head....

P.S. My timing slipped also...it was off by around 9 degrees on the exhaust side...

 

As far as I know my pistons are oem