I done one earlier this year.
You'll need
-New motor mounts and tranny mount, but they bolt right up.
-5.0 main and engine harness - Get the 5.0 hardness from the same year mustang and you won't have any issues.
-O2 wiring hardness
-Computer
-Fan - I went electric
-Hoses
-Radiator is the same
-H - pipe
-Cat backs
-All the muffler and tail pipe hangers
-Double hump cross member
-(2) O2 sensors
-Your T-5 trans will work; some say it's weaker
-Your 7.5 rear will work, it's a bit weaker and not a posi- I put in a 7.5 posi. The 2.3 should have 3.73 gears. Mine is holding up fine
-New tach or gauge cluster or your tach will read double
-5.0 throttle cable. The 2.3 one doesn't reach
-5.0 coil, my 93 2.3 had coil packs
-The starter is different, the 2.3 has a 3 bolt starter
-The alternator is on the other side. You lengthen the wires; I just upgraded to the 130-amp alternator and used a 2-gauge battery cable.
-The flue lines are on the other side - I used a 98-explorer fuel rail and 95 mustang fuel line extenders and I didn't need to mod the fuel lines.
-The driver's side rear brake metal line interfere with the exhaust - I was able to mod it to work.
-Cruise control won't reach the throttle body. - I deleted it.
- My car had a vacuum reserve tank- some years didn't have them
- My vacuum tree worked out fine.
- My brakes work fine - I didn't see a need to change them.
- The brake booster worked out fine
- Your 2.3 doesn't have a smog pump or the controls for them - I didn't add them -My car passed the PA smog inspection using the 2.3 VIN
- A\C compressor is different - I deleted A\C
- Power steering pump work fine - hoses can be used.
- I have an auto and I switched to an AOD - the tranny wiring was the same.
I spend about $2000 for the swap and thats not including the engine which I had and rebuilt. Everything is pretty much is a bolt up job. The fuels lines can be purchased which would make life easier than trying to modify them. If you can get a hold of a donor car, you will save $$ and plenty of time. I found that there is plenty of demand for these swap parts on ebay and the bidding drives the prices up high. The ford dealer is better source for some of the items.