MAC sometimes have some fitment issues but i've installed a good dozen sets and they always make it on one way or another. The real pain is if you run them for a year or so and then take them off....they heat warp and are a real pain to reinstall but still doable. I've never used FMS but i'm sure they're good quality. I would opt for something with a solid flange at the headers to avoid heat warp.
If its between either brand for you and it doesnt matter to you which, by god do yourself a favor and get the FMS. This is one of those products from Ford racing thats top shelf. If you really wanna spend the money and buy em jus once get the ceramic coated stainless steel headers. when you open up that box and see them youll thank me.
If its between either brand for you and it doesnt matter to you which, by god do yourself a favor and get the FMS. This is one of those products from Ford racing thats top shelf. If you really wanna spend the money and buy em jus once get the ceramic coated stainless steel headers. when you open up that box and see them youll thank me.
I've never bought Mac headers, but every other one of their products that I've had any dealings with has not been of the best quality and required significant persuasion to fit properly. However, I ran a set of FRPP stainless headers for six years before replacing them with FRPP ceramic coated ones purely for cosmetic reasons. Their quality and fit are excellent.