im running Flowtechs as well and have had no problems with the exception of the ends kinda touching my rear hangers on my front leafs, got them for 120.00 at pep boys, the way i look at is im running a pretty much stock motor and i dont think the brand of headers is gonna really matter as far as feeling a differance, now if your running 400 HP then i see a point in beening picky. besides any header is better than stock