Stock 1993 LX 5.0......What Bolt On Mods ?

Bolt-ons like CAI, MAF, TB, underdrive pulleys, intake manifold, headers, X-pipe and cat-back exhaust will improve throttle response and add some power when used together. My 1992 GT autocross car has those mods, plus 1.7 roller rockers and 3.55 rear gears. Those upgrades made a noticeable improvement over the stock setup. The power feels much more present and consistent.

The heads and cam are the big restrictions, so there's only so much power you can get without changing those parts (assuming you stay naturally aspirated).

Swapping in an aluminum driveshaft is a simple mod that will also help with throttle response and acceleration.

If you're looking to do a rear gear swap and a disc brake conversion, it's worth checking out the complete rear ends from MPS Auto Salvage in GA on Ebay. If you add up the cost of the parts and labor, the MPS rear ends can be a better deal. I put a 1998 Cobra rear end from MPS in my Fox and it has held up well under tough autocross conditions. They also have disc brake rear ends with Fox length axles.

Gears will make you think you added 50hp. HUGE difference.

With common bolt-ons, a tune/chip isn't required to make sure they all work together on a Fox. But, you do want to make sure the mods are balanced and the best choice to work for your application. A street car doesn't need long tube headers. You don't need a massive throttle body if you aren't doing other mods that would benefit from having one. Bolt-ons generally don't make an engine more likely to blow up; they are relatively mild mods. But, any engine, if abused, can go kaboom.

Fox Body Mustangs always benefit from a good tune-up, so make sure your plugs, distributor cap & rotor, plug wires and O2 sensors are all working properly. And check and change your oil regularly.

If you change rear gears, you will need to change your speedometer gear on the transmission, and the number of teeth will vary based on transmission gear and rear gear ratio. Other than that, if you aren't changing fuel injectors, you should just be able to bolt on the MAF, TB, CAI, headers, X-pipe and exhaust without issue. An intake manifold and roller rockers are more difficult to install if you don't have a lot of experience working on cars.

Iron GT40 heads will improve power and they match up well with the 1993 Cobra intake. You would want to run 24 lb. fuel injectors and get a corresponding MAF sensor. Installing a different cam will help you get more out of the GT40 heads. But, that becomes a more invasive build than you might have wanted.

No need to apologize for asking questions. We are all happy to help.

I do think it's worth taking some time to determine exactly what you want the car to be. A little bump in power/throttle response can be achieved without heads/cam/intake manifold. My autocross car has the stock heads and cam.