98 was the last year for the manual to be used in the sc's
found some info here
http://consumerguideauto.howstuffworks.com/1992-to-2000-lexus-sc-300-400.htm
Year to Year Changes
1993 Lexus SC: A passenger-side airbag went into 1993 coupes, joining the driver's airbag. A new automatic headlamp on/off system included a lamps-on warning.
1994 Lexus SC: Adoption of CFC-free refrigerant for the standard air conditioning was the only change for 1994.
1995 Lexus SC: Grilles, taillamps, and alloy wheels are new. The SC 300 adopted 16-inch tires, matching the SC 400. Both models got structural refinements to meet the stricter 1997 federal side-impact standards.
1996 Lexus SC: A new V8 engine went into the SC 400, borrowed from the latest LS 400 sedan. It produced 10 more horsepower (now 260) and 10 extra pound-feet of torque.
1997 Lexus SC: More aggressive-looking exterior trim and softer seats marked the '97 coupes. The passenger airbag moved to the top of the dashboard, and a trip computer was added.
1998 Lexus SC: Both engines were revised. The V8 gained 40 horsepower and 30 pound-feet of torque, courtesy of Variable Valve Timing. The 6-cylinder engine added 10 pound-feet of torque. A 5-speed automatic transmission went into the SC 400, with a gate for manual shifting.
No more manual-shift SC 300s were produced.
1999 Lexus SC: Daytime running lights were installed, perforated leather trim went on seats and steering wheels, and a new 6-disc CD autochanger became standard in '99.
2000 Lexus SC: One new paint color became available, and new perforated leather upholstery was installed. SC took the '01 model year off, reappearing in all-new from in '02.
(ask me why I know)
