BTW there should be a date code below the casting number you posted. It's a three digit number/letter/number in most cases. This will give you the exact year. The first digit will be the year ex: 4=74, 2=72 etc... second is the month "A" started the year as January so B for Feb etc... The last one or two numbers are the day of the month the block was cast on. Simple enough....G.