340 Manifold numbers question

My casting numbers list show 3614395 as a 73-74 318 LH manifold.
The 340 manifold is 2863553 for 68-71 340 LH for A body.
72-74 was 3614368 for 340 and 360's, these can be found on late production '71 as I have seen cast dates as early as May 13 1971.