Hey guys, quick question. My friend has a 351w in his stang with a gt40 lower and a downs box upper. He wants to get rid of the upper for a better low end, but doesn't feel like buying a whole new setup. I was curious, will the regular 5.0 GT40 uppers, fit onto a GT40 lower for a 351w? It is difficult to find the actual 351w upper manifold from an old 351w lightning or cobra, but I don't see why any regular GT40 wouldn't bolt up as long as the lower is for a 351w block. Let me know thanks!