A guy gave me a 250 the other day. It's still in a '72 C-10, but he said it had never been opened up before. I decided to see if I could see any over-size stamps on the tops of the pistons. I couldn't see any markings, but I thought these looked like factory standard-sized pistons. Any thoughts? The head gasket is genuine GM also. Again, could that be the original? And one more question-core shift? Leo's book says to look for a uniform 3/8" wide machine behind the water pump, but this one is kinda wild. I'm just trying to decide if it's worth pulling out and building. Thanks.
