Found a 318 - Not sure on year or numbers PLEASE HELP

Your casting number is 4104230, that is a run of the mill early 80s 318. Nothing special, and when you pull the heads dont be suprised if the head bolt holes are not cracked to the water jackets. I generally scrap those blocks, if you want to build a 318, try to find a earlier block, 67-74 or just go right to the magnum 5.2. Both are superior.