"Not Dad's" Duster

Son and dad new to site. bought a 71 duster and being our first mopar we have some questions regards to numbers decoding. my questions have been asked thousands of times. here are some numbers and locations they were found. block cast # driver side of block 2780930-340-8 . 11-18-69 with a clock pointer @ 12 with 2 dots @ 11 on the passenger side of block. Passenger side low @ pan believed to be last 8 of vin of original car -0B259831. Wondering what kind of car it came from ? Anyone here have that vin ?, clock pointer on pass side of blk D or N ours points to D for daytime I think, heads are stamped with an obvious J on both but pass head J is stamped backwards. Engine serial # from driver front of block is FW340P31220183. Is there anyway of telling what it come out of with this number ? we have a 1971 duster with a early 1970 340 that has the 6 pk- think the 6pk came later and not original. Thinking trans(727) and diff are original. we are in Wilmington Delaware , bought this as a entry level into this world and trying to learn all I can about it. thanks for any help or guidance. by the way old mopars rock. Sorry folks, posted in wrong forum !