First make sure it isn't a 5 bolt bell housing ..unless your motor is a 5 bolt bell housing . The swap is very easy.You will need the correct Flex plate ...AND MAKE SURE TO USE THE SHORTER FLEX PLATE BOLTS TO THE CRANK ,THE FOUR SPEED ARE TO LONG. Tranny mount is the same .You will need a floor shifter for a 65 -66 ,you will need a transmission cooler, unless your radiator is set up for it already .You will need tranny oil lines to hook up the radiator or external oil cooler .And you will need the starter for an automatic ,the 4 Speed has a shorter nose cone .You will need a passing gear cable to hook the passing gear ...and you will need a throttle pedal assembly for an automatic because the manual pedal assembly is not set up for the passing gear cable .