i commented in another thread : "as the buy-outs continue, the quality goes down" [or something like that]
as was mentioned above about a shipment of bad mounts.........
as to the OP, there is a diagram in either the engine book or the chassis book published by DC and MP, that gives engine location referenced from the crank centerline.
if it were me, i would get the engine set in that position, then see what is amiss with the mounts.
maybe the 318 K mount is off a tad, allowing the 318 to fit ok enough, but causing issues with the hemi and the conversion mounts.