D4AE-6015-AA 3 is the block code on the 351w i have. Below it is 4k28. I have already broken down the code most of the way but i was hoping someone could help me with the rest. D4= 74', A=Full Sized Car/Truck, E=Produced in Mahwah, NJ, 6015=Ford's part number for engine blocks, AA=27th revision?, and i'm not sure what the 3 is... 4k28=Produced on 11/28/74. So if someone could confirm what AA stands for and tell me what that 3 means that would be awesome! Also if it was produced as a late year 74 would that make it a 75? Or should i stick with 74? Thanks! Let me know if i got anything else mixed up!