340 block with NO main caps

as yr said
do not try and fool with matching up stock caps
use aftermarket caps and Line bore
this is not a job for a hone as hone will take too much out of the block
you could put 360 caps on it (if bolts are same distance apart- I think they are- give me a heads up if not) and use a 360 "stroker" crank" or even a 4" crank
I do not remember MOPAR but with (insert bad word here) we would put smaller caps on 400's and 350's and use a spacer in the block to run small bearing 283-327 crank
lots of ways to make this work