If your "74 " is one of the Model year that offered both a 2.0 L EAO and the 2.3L Lima engine, the clearances could be a mess. The 74 was a transition
Model for the Unibody, the Frame horns were spaced differently than the earlier cars, a new steering rack, and other dimensional nuances. In most cases the Starter has to be loosened or removed. Be specific about the problem areas and whether the headers are for the 74 based on production dates by VIN.
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Pintosopher