i am curious if if the header ball and socket flange would be in the same position as my old header? Also,i heard that it is bad to break in a new motor with new ceramic headers. it could cause damage to the ceramic coating.Is this true?
That answer lies between you and your exhaust pipes. The OE part numbers are different and you can bet the angle will be too. The 302 sits lower in the frame in the Mustang, higher in the Bronco. Any exhaust shop could make them meet each other.
Many other things are different between the two, even though both are a 302. ie; water pump , exh manifolds, intake manifold, timing cover, etc. To make it work in the Bronco is kinda just up to you and your modification abilities.