Incan and Aztec interaction

I'm sure that someone will come along to contradict this, but i believe the answer is no. The Azteca were Toltec people, and the Toltecs were relatively recent arrivals at the time of the Spanish conquest. The Aztec Empire was brand new--Moctezuma was only the third emperor--when Cortez arrived. The other Toltecs called them "Mezicans" (or something close to that) from which the Spaniard derived the name Mexico.

Pizarro arrived on the coast of South America much later. But the Tahuantinsuyo empire, of which the Inca was the emperor, was already much older than Toltec civilization in the central Mexican platueau. However, they had only recently began to significantly expand. The grandfather of the last Inca, Atahualpa, had pushed over the mountains into the region of the Amazon/Tigre River basin, but unsuccessfully. He had also moved south to the northern part of what is now Chile, and crossed the mountains into what is now Argentina. His invasion was stopped by the Mapuche in Chile, and other Araucanian tribes in Argentina. Atahualpa's father had begun the invasion of the empire of Quito to the north (modern Ecuador). Pizarro murdered Atahualpa, and effectively ended their empire (there was a subsequent puppet Inca set up by the Spaniards, and Manco lead a rebellion--but the empire ended in reality with Atahualpa). The Tahuantinsuyo never reached farther north than what is now Ecuador, and the Toltec never penetrated any further south than the northern belt of forests of central America.

My hunch is that they knew of each other, but didn't trade because of the geographical distances. We await the scientists putting forth their guesses.