I had a 72 also, I'm not sure what kind of engine it really had, Has anyone ever heard of a ball stud Hemi, I never heard of one either, I thought it was someone's idea of a joke so I parted it out, I think the engine is out in the barn somewhere, It has big valve covers but the spark plugs don't go through the valve covers like a 426, The valve covers were painted with black krinkle paint, My car was like Al's, it had a 4-speed and a Dana