Yes it will fit; the only difference between the two is that the 2.3 has a taller short block to equate for its longer stroke. Also the fuel rail will not be a problem, just use everything from your current engine minus the stuff I mentioned earlier.
If your exhaust manifold is cracked, it's best to just get another one or either get a patch welded on your current one. The exhaust manifold from the 2003 is the PZEV version which is more restrictive, so you wouldn't want that. Going aftermarket is also a choice, but then we're talking more money.