how do I tell what year/engine CIS is from
 

Have a chance to buy CIS but how do I tell year and for what engine

A good way to narrow it down would be to use the part no. on the WUR or the fuel distributor.

Post the number on this board, and somebody will help out with what year it's from.

There are dated casting numbers on each of the aluminum runners. They are usually one year prior to production. All of my '78 SC runner sets had "77" stamped on them. The '78/9 runners are larger in diameter than any other year.