will the intake manifold from a 2002 mustang v8 fit a 1999 lincoln town car

They're different part numbers but look to be physically the same, the Mustang plenum will not work with a heated pcv system though that the Lincoln probably has. All in all it's probably not worth the time or effort anyways the gains would be marginal at best. If you're looking for a small boost in power on the cheap and easy get a Lincoln throttle body, new gasket, a dremel with an assortment of grinding/ sanding bits, a sheet of 400 grit sandpaper and spend 10 hours porting the throttle body. If you're unsure how to do it put about 10 hours of research into it first, patience is the key. Every throttle body I've modded has been a complete success and has made a small but noticeable difference, mostly in throttle response some with the added benefit of slightly better fuel economy also. Sorry for the rant.