A number of years ago, I bought a rebuilt chevy 250 short block at a swap meet and pulled all my 230 parts off my original engine and finished off the 250 and it worked fine. I'm now doing some more work to the motor and am curious about what year my short block is. It has a large cast number on the passenger side of the block behind the distributor. There are three lines to the number: top line is 473483, second line is "GM", and the third line is 84. I've searched online for a block number like this, but there are none published that start with 4 or 47. Can anyone help me identify my motor?
