Converting a dual snorkel to a 70 71 340 air cleaner
Those dual rectangular snorkel air cleaners are worth some bucks too. If it were me I would look for an earlier oval snorkel one to modify.
I think the recess area was for AC compressor clearance, which is ironic since very few 340's actually had AC.
If you end up modifying that air cleaner I would be interested in the snorkels. I have one with a smashed snorkel I would like to refurb.