These two homographic words are all in nominal form, but the latter occurrence of '과장(kwacang)' in example (7) can be combined with a suitable suffix such as '-하-(-ha-)', whereas '과장(kwacang)' in example (6) can not.
when a homographic word '과장(kwacang)' appears with a conjunctive suffix, the first syllable of this word will always be pronounced as long vowel sound.