So far as I'm aware, you should be able to take that Mustang engine and with some parts swapping make it fit into the Town Car. Probably you'd just be using the block and heads from the 'stang and everything else from the TC's orig engine. It wont be a complete drop-in unless the FI system is the same, which I doubt it is. 88 should use an MPI system, and I think 85 and previous used a throttle body system. I'm not totally sure on this, but I don't think the heads are different from TB to MPI, so putting your 85 TB intake on should be no issue. Just have a good look at the intake bolt pattern on both engines and you should be able to tell.