[American Viking]

Well I typed long list of stuff to try since I've had an '87, '88, '93 and '90 Mustangs all with the 2.3l.
Only the '87 was an automatic and it pretty much turned me against automatics forever (try 4 transmission replacements under warrantee over 31 months and 24,000 miles - then when I finally got smart bypassed the dealer and got a new trans from a local transmission shop. Only to have Ford finally had a recall on the overdrives that kept failing a few weeks later).

I'm not one that is big on cross make swaps. Here is an example of how I upgraded my 2.3l mustangs.
The 88 coupe I drove to 130,000 miles, where #3 cylinder failed a section of the top ring put paid to the engine.
Rather than spend a chunk of dough just to get back a 2.3l four, I jumped in with a big lump of backyard engineering and swapped a 3.8l supercharged V6 from a '90 Ford Thunderbird Supercoupe into it.
I loved it, the wife hated it, and my youngest son's first sounds were vroom-vrroooom.