They didn't come that way, but, sometimes people swap out the 289 cam with a 351 cam and that gives the car the same firing order as a 351. I've never been real sure why people do that, since it doesn't improve anything, but, occassionaly you will find a 289 that someone has done that to.
3.8L engine, 1,4,2,5,3,6.
You have to be more specific. What is the engine size?
The 302 V8 engine available in the 1979 Ford Mustang has a firing order : 1 - 5 - 4 - 2 - 6 - 3 - 7 - 8 and the distributor rotates COUNTERCLOCKWISE
A diagram of the firing order for your 1969 Ford Mustang 302 engine can be obtained from most Ford dealerships. The diagram can also be found at most auto-parts stores.
What size engine? 302
You don't decide the manufacture of the engine decides the firing order. If you had listed the make, model, year, and engine size I could tell you the firing order.
http://autorepair.about.com/library/firing_orders/bl-fo-9189.htm Go here for ur answer has full view of cylinders and firing order for 91 2.3L mustang.
The V6 2005 Mustang firing order is 1-4-2-5-3-6
1-4-2-5-3-6
If it is out of order, yes.
1 - 3 - 4 - 2 The distributor rotor turns CLOCKWISE
Passengers side of engine, front to back 1, 2, 3.Drivers side of engine front to back 4, 5, 6. Firing order, 1, 4, 2, 5, 3, 6.