I thought the same thing!! I had a Magnum 318 that I bought already used in a carb'd application from a kid who put the oil pump on crooked (not in the pilot register in the cap) and was breaking in the cam and the oil pump shaft broke. He was away from the truck with it wailing, and heard it change tune, and by then the crank was smoked (especially the thrust, wtf?). He had it torn down and gave up when he found a 340 cheap. I assumed he had swapped pistons with LA units, until later when I tore down an unmolested late '90s truck for a customer and it had the same antique '80s pistons. Go figure!!