[bubbagump]

Original post:
1) Is there any differance in performance, all else kept the same?

2) Any differance in the sound of the engine?

3) Why did Ford change the firing order? Did they ever say why they did this?

I'm unaware of answer to question 1.
If there is a difference in sound it is subtle.

#3. Ford changed the firing order when they brought out the 351's both Windsor and Cleveland. The change was to address the earlier firing order, 15426378 the OVERLOADED the front main bearing.