I will assume you have a transmitter that is FM. If not you will need a whole radio. You cannot economicly convert the old AM radio's to FM. If you do not have the transmitter I would suggest you get a Futaba 4 channel package. It would cost you about the same as the components. If you have the transmitter then You could just get a new reciever and battery and change the plugs on your old gear, that is one way. The best way would be in my opinion if you have a transmitter on FM is to buy a flight pack. I like the Hitec ones. They have good components at a good price. Just remember to get a crystal in the appropriate channel. Futabe flight packs must be bought in high or low band. Up to channel 35 is low band after 36 is high band. I would highly reccomend the new flight pack idea. Best of luck.

Mark Shuman