Say I am a high level cleric. I have Flame Strike prepared with Empower metamagic, increasing it's spell slot by 2, resulting in an Empowered Flame Strike sitting in a level 7 spell slot.
I also have a normal metamagic rod of Intensify which affects spells of level 6 and lower.
Can I use my metamagic rod when I cast my Empowered Flame Strike? On one hand the level of the spell is still <6, but on the other the slot it uses is >6.