I have a GM 5.0LG/SGI stamped on the drivers side, and the casting number on the passenger side is 16093627. I couldn’t find this casting number anywhere but noticed if I switched the 6 for a 4 it’s a Chevy 305. Is 6 a casting mistake or some other reason. It’s a boat and had a rebuilder company build me a 305 Chevy to replace my 87’ 305 Chevy Camaro engine. Thanks
