Also in Japan, the 610 was initially sold alongside the 510 but eventually replaced the 510. 610s were available as a four-door, two-door hardtop, and a five-door wagon/light van. Trim levels in Japan were GL (Grand Luxe), SSS (Super Sports Sedan), DX (Deluxe) or STD (Standard). It borrowed its suspension and drive train from the outgoing 510, with some modifications. Likewise, the 610 four-door and two-door retained the class-leading, independent rear trailing arm design, while the wagon reused the rear live axle with leaf springs from the 510 wagon. Whether four or six-cylinder models, all 610s were equipped with Nissan's L-series inline engines. In many export markets, including UK, Europe, and Australia, the 610 was badged as the 160B or 180B with respect to particular engine displacement. The Bluebird name also often appeared in advertising and in brochures. In the UK the popularity of the 160B/180B/180B SSS Coupe range further strengthened Datsun's position as the leading Japanese importer. As a result of Japanese Government passage of emission control regulations, Nissan introduced their emissions technology in 1975, using a badge that said "Nissan NAPS" (Nissan Anti Pollution System) on vehicles thus equipped. Most 610s worldwide came equipped with either a four-speed manual or a three-speed automatic transmission, but a five-speed manual transmission was available in the Japanese and Australian markets. As with the 510, the SSS trim included miscellaneous sport options and a higher output engine with twin-Hitachi carburetors. A Japan-only SSS-E model was equipped with Bosch-licensed electronic fuel injection, and so was one of the first, mass-produced Nissan vehicles to be sold without a carburetor. Another 610 never exported was the inline-six U-2000 GT and U-2000 GTX (nicknamed "shark-nose" in Japanese), which shows some visual similarities to the Pontiac GTO and Oldsmobile Cutlass. Called the G610, it came with a stretched front end to accommodate the longer engine and featured a different grill and other aesthetic modifications. This model was not available as a wagon. The most powerful GTX-E received fuel injection and . The 610 Bluebird received a facelift in 1974, with prominent turn signals mounted on the front corners and with a more squared off grille as well as new taillamps. The SSS models now had styled steel wheels without hubcaps. New equipment such as a remote trunk opener, interval wipers, a central handbrake (rather than the earlier "umbrella style" one), and new interior materials accompanied the external