Well, the gear stuck in park is a safety feature due to the ignition not being turned over -- a pain in new cars, since you cannot easily shift to neutral for a tow when your key is lost. Have you consulted a repair manual for the ignition installation? I've only done an ignition once, and it was easy, but on an old 67 Mustang. There were grooves to make sure the ignition could be aligned only 1 way. Does everything look aligned correctly, ie does the key point to the correct indicators for off, acc, on, etc? If so, I'm not sure what the problem is, but maybe try the ignition switch for rotation when it's not installed . . .