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 .