Browsing through Facebook marketplace for stuff I don't need, I came across a 318 the owner swears is a race block (casting number 4104230-318-4). Doing some research, several sites list it as a race block except for the site (mopar casting numbers) says it is a '76-'84 standard block. I wonder what the deal is. I also did read a similar post on FABO about these casting numbers and that one stated it was more than likely a standard block. I know the X on the front of the block is a dead giveaway but I'm still curious about your thoughts on the block and why there would be so much conflicting date on that specific casting number.