The picture says it all... Where do I go from here? The valves don't look bent but should I pressure test them? I have to pull the motor and swap the pistons around; will I have to re-hang the rods so they can all go back into the same bores?

 

Getting the heads checked would be a good idea. Honing and re-ringing should be enough to swap the pistons from side to side.

 

What about the rod offset?

 

They're aftermarket pistons, I doubt they have a rod offset.

 

Is a re-ring imperative? The motor has less than 4k miles on it.

 

The rings are broken-in to the cylinders they're in now. They won't seal in different ones.

 

Ahhh ok, I see what you mean... yeah, they'll probably have to be rehung.

 

I'm willing to bet the guy who put the motor together put half the pistons in wrong... won't know 'til I pull it.

http://www.jepistons.com/TechCorner/Pin-Offset.aspx

The pistons did seem really loud when cold.

 

Those pistons probably don't even have pin offset. The problem is the connecting rods. They have a side that has to face the other rod on the pin, and a side that faces the crank throw. Essentially you need to turn the piston 180 degrees without turning the rod, which can't be done without taking the rods off.

 

I'd be having a little chat with that guy.

 

Thats just bad workmanship. you can clearly see were the valve was contacting the piston, so they are most likely damamged in one way or another. Best thing to do would be to pull each rod/piston assembly at a time, pull the piston off the rod, and rotate it 180 degrees. then reinstall with new spirolocks on the pins. and i would most def have the heads checked out for bent/damaged valves.