Look for the letters stamped below the right head and the casting date by the distributor. That will tell you exactly what it came out of.
The number you posted doesn't mean anything. The letters after the number stamped on the pad with it will give at least a close indication of what it came out of. http://www.nastyz28.com/chevy-engine-code-stampings.php The casting number on the back of the block here. http://www.nastyz28.com/sbchevy/sblock.php I'm like the others though, if it's a 350 it's a 350 Then the differences are two bolt mains or four bolt mains and two piece rear seal or one piece rear seal and flat tappet cam engine or roller cam block. It doesn't make a rippy doo dah what the hell it came out of originally unless you are hunting for bragging rights and a four bolt main block out of a Van won't be impressive enough at burger biggie on cruise night.
I'm guessing the number posted is a vin derivative...the numbers you should be looking for are to the left of the vin....but my guess is a 76 Corvette 350 4 barrel engine judging by the vin..
Its more the 16S part..the 1 is chevy of course..the 6 is either 66 or 76.. but since you said it was a 350..I went with 1976. The most important is the S which is the plant..St. Louis..which is where the built vettes..sometimes if they made more than one car at a plant the number part in this case starts with 400k is Corvette...Impala might be 100k or something like that