I have a friend who was working on gearing for a Civic which consisted of some pretty crazy metals and alloys, the fact of metals like Titanium costing an arm and a leg along with the cost of programs like Cad for the schematics of what you want, with the cost of machining those items....I don't know about anyone else, but I don't have a lathe in my livingroom.....we're kinda stick at the present moment, unless you have some serious cash, the best option would be BRAND NEW OE