If you have ever tried to put bolts in the end holes on 1972 or 1973 Pontiac 7K3 casting number heads, you know there are no bosses or material for bolt holes for the exhaust manifolds or headers. You can't even drill or tap a hole for the bolts, and even if you could, you'd have to remove the heads to do it. This L-bracket solves the problem by bolting to the back and front of the head through existing bolt holes and has a stud mounted on the exhaust face of the bracket that will go through the end bolt holes of either exhaust manifolds or headers. The brackets provide a secure surface for the exhaust manifold or header to seal against on the 1972-73, 7K3 heads.