Most likely, the heater you have in your small aquarium will not be sufficient for a large 80 gallon tank. And your little filter will definitely not be suitable. It's filtering capacity will be a drop in the bucket compared to what is needed for a large tank.
At the very least, print out the page for the Aqua-clear 110 on the petsmart website and go spend $40 using their in-store price match policy and you will have a good start toward having enough filtration for that tank. If you stock your tank any more than lightly, youwill probably want another AC-110 also. . .
But there is no reason you can't also keep that old filter on the 80 gallon tank. Every little bit helps. I actually have a silly little Penguin Biowheel MINI on my 75 gallon (along with an Emperor 400, an Emperor 280, and an Aquaclear 110). It is only on there temporarily to keep its bacterial colony alive while it awaits being placed on a new 10 gallon that I am cleaning up this weekend