mopar-mike's 71 duster project

alright got the motor out, got the six freeze plugs out that hide under the headers, all the other ones looked good. also went ahead and dropped the trans all the way out the bottom pic is it and the starter. 904 trans and 318 engine i thnk they are original to the car, but they both seem to have been gone through recently. here are the numbers that were stamped on part of my block (2536030 318-9). anyone have a clue what that means or how to decode it? it is a 70 block. there are more numbers on it but i forgot to write them down.lol