Not sure on the exhaust air injection holes but studs on the rockers and vertical intake bolts along with the magnum style head bolts lean towards magnum. Like I said the earlier 5 bolt cover can bolt on a magnum with the 8 hole gasket. It could be glued ti insure it does not leak. Looking at those exhaust ports has me thinking the magnum did not have the injection holes. Also that head had many other identifiable casting features that tell me it is not a pre 92 casting.