The Slant-Six is the popular name for a Chrysler inline-6 internal combustion engine with an overhead valve reverse-flow cylinder head and cylinder bank inclined at a 30-degree angle from vertical. Introduced in 1959, it was known within Chrysler as the G-engine. It was a clean-sheet design that began production in 1959 at and ended in 2000 at . It was a direct replacement for the flathead Chrysler straight six that the company started business with in 1925 until the old design was discontinued in the 1960s. Design The Chrysler Slant Six engine was a clean-sheet design, led by Willem Weertman, later Chrysler's chief engine designer. Its characteristic 30° inclination of cylinder block gives it a lower height overall engine package. This 30° inclination had already been used by Mercedes-Benz in their 300SL sports car with the M186 engine since 1952. This enabled vehicle stylists to lower hoodlines, and also made room for the water pump to be mounted with a lateral offset, significantly shortening the engine's overall length. The slanted cylinder block also provides space in the vehicle's engine bay for intake and exhaust manifolds with runners of longer and more nearly equal length compared to the rake- or log-style manifolds typical of other inline engines. The No. 1 and No. 6 intake runners are of approximately equal length, the No. 2 and No. 5 equal but shorter, and the No. 3 and No. 4 equal and shortest. This has the effect of broadening the torque curve for better performance. The Slant Six manifold configuration gives relatively even distribution of fuel mixture to all cylinders, and presents less flow restriction. This, in turn, provides for relatively good airflow through the engine despite the intake and exhaust ports being on the same side of the head rather than in a crossflow arrangement. It was introduced in two piston displacement sizes in 1960: The "LG" (low-G, referring to the relatively short engine block casting and crankshaft stroke) in the Valiant, and the "RG" (raised-G, referring to the relatively tall engine block casting and crankshaft stroke) in full-size Plymouth and Dodge Dart models. In 1960, the engine was called the "30-D Economy Six" engine by Plymouth marketers, referring to the 30° cylinder block angle. The G-engine was offered in various configurations in the North American market until 1983 in cars, 1987 in trucks, and 1991 for marine, agricultural, and industrial use. Replacement engines