I was looking at a 383 5.7 stroke rods with afr heads and supposedly 9:1cr. He thought it was, but was not sure. The pistons in it are SRP 40D. The number is casted into it. I was wondering if the motor really is a 9:1cr. Does any one know of this number? I looked on SRP website but couldn't find a 40D. Can someone please help me out. Thanks.....John