I have a late build date of 09E (sept 69) X22 4-speed camaro that is missing the original block. I found a 3969854 4 bolt dated H 31 9, the block has beed decked clean. The heads are 3964291 square ports dated I 10 9 & I 12 9. Does any one know if the late built camaros use the JH code disginating a 396 CI or did they change over to the 402 CI with a C - - code.