Is there any differnce from a 83 or 84 5.o mustang ho engine to the 5.0 i have in my.

[DuceAnAHalf]

Including Air? From the factory, the 351 definitely uses a different AC bracket.

Ac bracket i dont know, i junked that. but the alt and PS bracket fit perfectly, you just use different bolt holes.

And The headers will only fit a car WITHOUT a coloum shift, they will run right into the linkage. Not sure if they will work with AC because they might interfear. Also, would require a little more modification to clear the steering shaft with rubber mounts, i have about 1/4" clearence minimum, not sure how much rubber mounts will let the motor rock.