If I had to use one of the gaskets pictured it would have been the bottom one.. Why??/ Because the coolant passage is ringed in rubber and wont leak. But if my choice was widened some I sure would use the 6.9 head gasket on any 7.3 block and heads. I would open the plugs the same amount that the 6.9 insert has in them. I know of several engines running 6.9 gaskets on the 7.3 with opening up the plugs as I mentioned. No problems either. Brian you can still remove the heads and install 6.9 head gaskets.