See if you changed banks for the pistons if the valve reliefs and squirt hole/anchor slot will be in the proper orientation... If you can't fix it by changing pistons from one bank to the other, then:
If the pistons have floating wrist pins, then you can fix it yourself... Just remove the wrist pin clip from one side of the piston and slide the wrist pin out...
The arrow on the top of the piston should point to the front of the engine, and the connecting rod squirt hole should point towards the middle of the engine (Towards the opposite cylinder) and the anchor slot on the rod for the bearings should be toward the outside of the engine block...
One bank will be the opposite of the other....
If the pistons have press fit wrist pins, then you need to take them back to the machine shop and have them fixed as I stated above... ^^^^^
