Anyone know where I can get custom length steering shaft stock with different types of couplers installed on them? I already contacted Flaming River and they are contemplating it. I need to go from a stock 67 Coronet steering gear output shaft that's splined with a master spline to a 2004 Audi swivel coupler that's a 1/2" slot without splines. 18" overall including inside length of couplers. So, 67 Coronet 5/8ths splined coupler on bottom end and 1/2" smooth square shaft on the other end.