340 block stamping info needed

[Tonefiend]

I have this 340 block I am going to turn into a motor one of these years and am curious about how to read the stamped numbers.  Here is a pic.  From what I can see it reads: EW340P28030172

Ok so I have been able to decipher E=1969   W=Windsor plant  340=340 C.I.   I don't know what the P means and what the other numbers are for. 

Also check the stamp below. I hadn't noticed that until I saw the picture.  It appears to say E4

Thanks!

[Cuda Cody]

Just a guess....  2803 is the 10,000 date code (March 31, 1969 and it's the 172 block stamped that day.   

[Tonefiend]

Thanks Cody!  Any ideas on the P or the other stamp anyone?

Also, where would I find the Vin stamp?

[Culvers]

P = Premium Fuel

[Tonefiend]

Cool, thanks!  I guess I'll have to run premium in it then.