Hi everyone, does anyone happen to know what the 107 means on the pad behind the timing cover? It says 107XCH. I know what the XCH means but not the 107. I have a 71 SS Elcamino that has this crate motor in it. Thanks in advance for your input. Doug

 

There should be two more digits/alpha code to the left as well. This represents the Factory serial number for the block.