The Engine ID pad up on the block by the cylinder head would be where I'd start first. It tells how the engine was built. It should have stamped into it something like
C383Pxxxx.
Other marks scattered around that pad will tell you any factory oddities, like one rod bearing is undersize, or one lifter bore is oversized, etc.
Next in importance would be the casting date, cast into the side of the block.
Third (for me) would be a number stamped into the machined pad just above the oil pan. But depending on the year, it may either not be stamped or not be there.
R.
The casting number is 2468130. The dash number, in this case 7, has something to do with how many times the casting core was repaired, IIRC. In reality it means nothing.
Last edited by dogdays; 05/19/15 03:48 PM.