For an 05 F-150 4.6L you only need one set of catalytic converters right? And they have to have an 02 port on them? I'm about to redo my whole exhaust with a set of pacesetter longtubes, two magnaflow high flow cats, an x pipe and two dynomax bullet mufflers, am I missing anything? I've heard to reuse the stock gaskets when installing the headers in order to prevent leaks. Any input would be great. Thanks.