1970 Dart Swinger FINALLY UNDERWAY

Well the thing is,aluminum heats up faster than steel so the piston "could" swell and cause the wrist pin to shift out one side.But if it did that it would still be shifted so I'm beginning to think that motor was rebuilt and those pistons were put in and the clip wasn't removed and got into the scored piston(this is just a guess).it's been awhile since I rebuilt an engine so I may be a little fuzzy on the factory pistons but I thought the factory ones had wrist pin clips.BTW that 360-3 from what i've read on here is thats the 3rd casting for that 360 block.Nothing "special" about it.