Chevelle frame stamp numbers

[Billohio]

Friend of mine found these on the frame of his 72 chevelle. Any ideas what they are?

[m22mike]

Hi Bill
Common on Chevelle frames. PN, maybe a vendor mark. The lower row is a date code. Hard to make out all the numbers there. Found one on Grady's 69 frame. I will look for some examples.
Mike

[Mr70]

Everything you ever wanted to know HERE>.http://chevellestuff.net/qd/frames.htm

[Billohio]

Thanks guys I will pass that along!