Hy Colin, You could use your present ignition switch and just add a push button switch for the starter function. The automatic installation is a little harder, the 400 was designed with a rear mount in mind, so no mount at the back of the engine, some people think that using the stock 55-59 V8 engine mounts which mount off of the engine and a trans with a rear mount results in too long a span between mountings. I can understand their concerns, I have seen at least two ways to deal with this, a kit to put side mounts in the truck frame for the engine, or a kit to put mounts on the front of the transmission using the bellhousing bolts, hope this helps
