How to tell the year of a block?

[jimmybeus]

Ok here are my next questions. I got another motor for my 86 k10. The p o said he thought it was a 72 but not for sure. I can see the numbers on the front and back of the block and just wondering if they can tell what year it is. I am also thinking of putting on a gear driven timing set. Anyone running with one and if so how do you like it or performance advantages. I am mainly going for the noise but any advantages will be a plus. Thanks in advance.