Retro LS3 Build

This LS3 engine was built by MAD Customs and later featured in All Chevy Performance magazine. The project focused on giving a modern LS3 the look of a traditional Chevrolet small-block while keeping the performance, reliability, and drivability of modern LS technology.

We started with a new GM crate LS3 and completely prepared the engine for refinishing. The machined surfaces were blasted with aluminum oxide and the engine was epoxy primed before being finished in Chevy Orange urethane.

A Holley oil pan was installed for additional ground clearance, and the factory intake and valve covers were replaced with components selected to create a more traditional appearance.

The intake system consists of a Holley EFI single-plane intake, GM 42-lb/hr injectors, Holley fuel rails, and a 1,000-cfm Holley throttle body. A reproduction Goodmark C10 four-barrel air cleaner was added to complete the vintage-inspired look.

We installed a Billet Specialties retro-style valley cover and valve cover adapters. The adapters allowed the modern ACDelco ignition coils to be mounted underneath the valve covers, keeping the coils hidden and creating a much cleaner engine appearance.

The valve covers were painted Chevy Orange to match the engine and finished with hand-lettered Chevrolet script.

For the front accessory drive, we installed a Holley Mid-Mount Accessory Drive system, including the water pump housing, 150-amp alternator, Type II power steering pump, and Sanden SD7 A/C compressor. The compact design keeps the front of the engine clean while providing the accessories needed for a modern street-driven vehicle.

Additional details included a Lokar flexible oil dipstick, serpentine belt and tensioner, custom-fabricated fuel crossover hose, and stainless steel heater hose fittings.

The finished LS3 combines modern performance and reliability with the appearance of a classic Chevrolet small-block.

Built by MAD Customs. Featured in All Chevy Performance magazine.