If you are talking about r&r the same, or similar heads, nothing out of the ordinary. Passenger side is tight with the ac box, but will come out with engine in car. If you are changing to aluminum heads you can get into pushrod lengths and rocker arms specific to the manufacturer of the heads. Gaskets, graphite vs MLS, also have different install methods and prep to block surface. Head studs need to be put in with the heads not before due to the ac box if you plan on using those, again if engine is in car.
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