So ive got two sitting here. Wondering which to cut open and port out. My choices are my factory 01 Cobra lower, or a 2004 Merc Marauder Lower. Ive read on the SVT website that the marauder/mach 1 outflow the 01 Cobra lower by 20-30 cfm PER RUNNER, and almost 60cfm per runner compared to the 99 fixed versions. But looking inside them both, they look identical... Is the difference the bells inside the lower or what? Does anyone on here have an experience with the three different lower intakes? Has anyone on here ported their own? I have access to aluminum welding equipment. If i dont cut it opent and just smooth one out, get rid of the high bumps and BS you can see down inside would it be worth it? Or should i just cut that sucker open and go to town on it? Noticeable gains? Id honestly want to be cutting a mercury marauder part rather than a factory cobra part.... So hopefully the merc lowers do flow better even though they look EXACTLY the same.