340 casting number question

[Sluggo]

Have a 70 340. Looking at the side, it does show the casting number 2780930 but not the '340' after it. Any idea why? VIN pad is blank also. Pics below.

[Cuda Cody]

It looks like the block was ground down to the right of the casting number? 

[Mr Cuda]

 Well, the factory could have messed up making a 273 in an outer block casting for a 340. Maybe a warrantee engine? Any vin number?
 What kind of heads? 2.02 340 valves will not clear a 273 bore.
 It does say 273 on the block i.d. but it looks like the vin is following.
 Maybe the 340 was ground off and 273 was stamped to fool class racing rules way back when.
 Pull the head.

[340challconvert]

Very odd; does look like the numbers were ground off. The 2780930 cast number was used on 68-73 340 blocks. The numbers"273"look like they were added? The numbers prior to the 273 should read FW340P + 4 digit number (assembly date) and 4 digit number (engine assembly date.) F for 1970, W for the Windsor plant, and P for premium fuel. If you look to the left, I enlarged the pic; something was ground off! Be interesting to use a drop of acid in that area to see if anything can be read! The numbers/letters should start at least an inch further to the left then what is on you block. (Compare to my sample pic). It could be a warranty replacement block? I posted a sample pic of what a code would look like.

[6bblgt]

  class racer's "STOCK" 273 right there   

[Sluggo]

It has 2.02 valves so is a 340. Maybe was a 'fake' 273... dunno.
Have another 71 block with strange stamp on block also-see

[6bblgt]

H = 1972 model year    looks like the stamping started a little too far left, so it got a second line
3765 = 11/18/71 engine assembly date (EAD)

what's the partial VIN stamped on it

[Sluggo]

Pic of 72 block VIN. On assembly stamp it shows a diamond at the end and from what I remember it means oversize lifter bore. Not sure how to find lifters for this one.