Will a stock 460 engine fit in to my ford 1989 crown vic, trying to convert to 4x4?
Yes it will but you have to adjust the mounts, install new suspension to hold the added weight. Add a C6 Tranny and you're off and running. They do have mounting kits available for this, try ebay. Buy american though, the Chinese stuff might be cheap, but its not something you want to break on you.
Was the crown vic an old cop car? If so that might be easier to do. The 460 is about the same width, but it is a little longer. Cut the mounts off and have them re welded to fit. I have heard of a few people doing this with just some knuckle bashing for a while, but it will fit with some know how.