Anyone decode a 340 block?!?

I found a guy selling a 340 block and crank. I asked him some questions about them and this is what I got back from him...

It is a block with a crank, it is rebuildable, as far as the crank, it is the original crank that came with the block when i bought it. No pistons, No cam shaft, just the block and crank. numbers as follows, as best i can read.......IM 340 P 40 //D or Z, 0 or 2// 8151, 2780930-340-1 4, 3 B 1 76990. thanks....

Can anyone help me decode this block? I asked whether the crank was cast or forged, and you read the reply I got back. I know how to tell by looking at the balancer, but not how to ID the crank by looking at it. Any help?


Tell the guy to send a good, clear picture of the crank and post it here.
A cast crank has a thin part line. The forged crank has a wide part line.
Also, if you hit (lightly) the crank on the snout with a ball peen hammer, the cast crank gives off a high-pitched "ping."
The forged crank, being denser, gives off a "thud" when hit.