Hy oldbluetruck, as we said, you'll need to purchase an adapter kit to install anything but the original Hydramatic or early powerglide. You'll have to install a transmission rear support crossmember, and probably something to support the back of the engine. A new or modified driveshaft will be needed. You could install a floor shifter, or a newer column to shift the transmission, you should install a transmission oil cooler in front of the radiator. There may be some throttle linkage to fabricate to get the transmission to shift correctly, and/or some wiring to do, anyway you slice it, it is a little complicated to swap in an automatic. I don't want to scare you off the job, but I also want you to know that it is a little involved, we will always be here to help.
