No pics but it is a 383. I am not sure if the block is original, but I know the heads are not. When I buy plugs, I have to tell them they are from a 70 blazer, because the plugs for the 77 are too big. Any clues? Where do I look to reference. I am alway limited in my plug selection due to this. I know this is a general question, but hopefully the engine experts will have some input.