timing set and engine verification

Does anyone knwo how to tell what year an engine is? I have looked over the block and cannot find any id numbers, am I not looking in the right place? Also what is standard timing setting for a stock 350 engine?? The engine is in a 72' chevy truck. any help would be appreciated. Thanks!!

You need to find the casting numbers on the block. Read this link to find out where they are and which engine you have: http://www.mortec.com/castnum.htm

//2000CAYukon

Timing should be anywhere between 4 to 8 degs BTDC with vacuum hose disconnected to the distributor and plugged. Casting #'s are usually cast into the back of the block(very hard to see). Serial #'s are stamped on a flat boss just forward of the right side (passenger) head.