Nitto Billet Crankshaft 79mmSuit 2. 5 Litre WRX and STI NITTO 4340 Billet Steel crankshafts are manufactured from high quality true billet round bar stock. Most other aftermarket crankshafts are manufactured using cast forged material, which is a much cheaper manufacturing process and hence carry a cheaper price tag but their performance, strength and horsepower capabilities are significantly compromised compared to that of a true billet crankshaft. An engine with a 4340 billet