Chevrolet small-block engine
In 1992, GM created a new-generation small-block engine called the "LT1 350", not to be confused with the high-output Generation I LT-1 of the 1970s. It displaced , and was a 2-valve pushrod design. The LT1 used a reverse-flow cooling system which cooled the cylinder heads first, maintaining lower combustion chamber temperatures and allowing the engine to run at a higher compression than its immediate predecessors.
Chevrolet small-block engine
The early Optispark distributor had durability problems and a revised version was introduced with vacuum vents to remove moisture and ozone on the 1994 B-Bodies and in 1995 on the Y and F-Bodies; the vacuum vents can be added onto earlier distributors. 1996 saw major revisions for OBD-II: a second catalytic converter on the F-body cars and rear oxygen sensors to monitor catalyst efficiency. Some OBD-II features had been added to the Corvette starting in 1994 for testing purposes. The 1997 model year Camaro and Firebird were the last year for this engine in a GM production car before it was replaced by the LS1, which was already in the Corvette for 1997.