I figured I post some pics of both the 351 and 401 head gaskets for comparison, in the pic with the two gaskets side by side the one on the bottom is an OEM 351 head gasket(with "Victor" stamped on it) and on the top is a 401 gasket. You can see how the 351 gasket has oblong holes in order to make clearance for the valves to go through. The other pic shows the 401 gasket on top of the 351 gasket