340 block casting #

The block you have is the 2780930 block for 68-73.The (D)is for the day shift.The 9b331245 is the year,assembly plant,sequence number.Its a 1969 block,built at the Hamtramck MI plant,and was the 331,245 motor built.The crank if it has a 1/8 parting line down the length of the crank,its a cast crank.This is a problem,as all the origanal cranks for the 340 are forged,so check the codes and marks to be sure.Check for paint marks and codes on the number 6 counter weight to be sure.The L5 and the R8 are these on the deck surface or on the casting of the block,Mrmopartech