Its phaseout marks the end of an era of Chevrolet small-block engine designs dating back to the 1955 model year.

A new Generation V 4.3 L (262 cu in) V6 variant entered production in late 2013, based on the LT1 small block V8 and first used in the 2014 Silverado/Sierra 1500 trucks.

To create a true even-fire engine, Chevrolet produced a crankshaft with 30-degree offsets between each rod pin.

Some 1985 model year vehicles would have a 1986 engine due to service replacement – cylinder blocks were shipped with oil pans.

[4] For the 1992 model year, the 4.3 L (262 cu in) had its block design modified to allow a balance shaft to be installed.

The balance shaft on the 4.3 L (262 cu in) is installed above the camshaft and runs through the middle of the lifter valley.

For the 2007 model year, the distributor was eliminated in place of a coil-on-plug ignition system (using a 58x crankshaft position sensor based on the GEN IV LSx).

This resulted in a redesigned timing cover with a wider bottom flange, making it incompatible with the 1996–06 LU3/L35.

The LB1 used in trucks and vans was referred to as Vortec in Chevrolet literature (named after a combustion chamber design known as a swirl port which twists the fuel mix from the intake ports as introduced with the Cavalier's 2.0L engine), and this name continued to be used with all truck and van 4.3 L (262 cu in) V6s until 2014.

In 1987, the Chevrolet full-size pickups and vans were upgraded to use the LB4 throttle-body injection version of the 4.3 L (262 cu in).

Legend For the 1990–1991 model years, a high-output 4.3 L (262 cu in) V6 was an available option for the extended-length versions of the Chevrolet Astro and GMC Safari vans.

The fuel injection was a batch fire system and used a two piece cast aluminum dual-plenum manifold.

Timing cover flange area was thickened in 1995 when some of the balance shaft motors had a six-bolt timing cover; some engines had a crankshaft position sensor (in conjunction with a redesigned distributor containing a pickup assembly which functions as a camshaft position sensor) when OBD-II was phased in.

Like other small block Chevrolet V8s, the 4.3 L (262 cu in) engine received redesigned heads which had improved airflow and combustion efficiency.

These 4.3 L (262 cu in) (1996–2000) engines came with a redesigned 4L60-E transmission with a removable bellhousing which bolts to the oil pan.

Crankshafts manufactured for the 1999 model year (to the end of 4.3 L (262 cu in) production) had a pilot hole depth of 1.41 in (35.8 mm) when coupled to the LSx-based 4L60E, which had a redesigned torque converter pilot hub (which was longer and was used with a 300 mm (11.8 in) stator shaft).

The torque converter pilot hub was longer than the early 4L60E (similar in appearance to the 1993–1995 700R4) or the second generation variants (incorporating a removable bellhousing) with the GMT330 or 1996–1998 C/K series.

These engines used a multipoint fuel-injection system, with six Multec II fuel injectors mounted at each intake port on the manifold.

The sticking poppet valves have been attributed to ethanol fuel blends sold in the State of California.

The LU3 also received a "quiet cam" to help reduce vibration at both idle and high engine speeds.

For the 2007–2013 GMT900 Silverado/Sierra 1500 trucks and 2008–2014 Express/Savana 1500 vans, the LU3 engine received a Distributorless Ignition System: the traditional distributor was eliminated where a stub shaft was used.

This engine used a Mitsubishi TD06-17C turbocharger, Garrett water/air intercooler, and electronic multi-point fuel injection.

Like its small-block V8 counterparts, GM Powertrain has also sold the engine for marine and industrial applications.

GM considers this a new engine design which inherits from its predecessors its displacement, 2-valve pushrod valvetrain, 90-degree cylinder angle, and 4.4 in (111.8 mm) bore centers.

It is based on the fifth-generation LT engine and includes the same features such as direct injection, piston cooling jets, active fuel management, variable displacement oil pump, continuously variable valve timing, and aluminum cylinder heads and block.

Emissions are controlled by a close-coupled catalytic converter, Quick Sync 58X ignition, returnless fuel rail, and fast-response O2 sensor.

[13] 2021 was its final model year in the Chevrolet Silverado and GMC Sierra 1500, as the 6-speed automatic transmission was phased out.

The Chevrolet Express and GMC Savana are the last vehicles to use the 4.3L but do not feature Active Fuel Management and their version of the engine is referred to as the LV1.

The LV1 made its debut in the 2018 model year GM full-size vans—the 2018 Chevrolet Express and GMC Savana—as the successor to the 4.8L Vortec engine.