D&J Precision Machine launches two upgraded LML Duramax long blocks

D&J Precision Machine has released two remanufactured long block options for 2011-2016 Chevrolet Silverado and GMC Sierra HD trucks with the 6.6L LML Duramax. The Precision Plus and Essentials engines are designed to address common failure points, simplify replacement work and give owners and repair shops a higher- or lower-cost option.

Why it matters: - The new long blocks give Silverado and Sierra HD owners a replacement path for a known problem engine platform. - D&J is using its Cummins engine-building experience to expand into the Duramax market. - The launch creates two choices for shops and owners: a more complete premium build or a lower-cost rebuild option.

What happened: - D&J Precision Machine introduced two remanufactured long block engines for 2011-2016 Chevrolet Silverado and GMC Sierra 2500HD and 3500HD trucks with the 6.6L LML Duramax. - The new products are called Precision Plus and Essentials. - The engines are available now through D&J Precision Machine and BD Diesel. - D&J is based in Cambridge, Ohio.

The details: - Both long blocks are fully disassembled, cleaned, inspected, precision machined and rebuilt to D&J specifications in-house. - Each engine uses CNC blueprinted, bored, honed and deck-surfaced blocks. - D&J inspects each crankshaft for straightness and dimensional accuracy. - The rebuild includes new OEM-spec Tier 1 pistons and rings. - Keyed crankshaft and camshaft gears are used to help prevent gear slippage and preserve timing. - Remanufactured cylinder heads get recut valve seats, new valves and upgraded L5P top-hat valve stem seals. - Bearings, thrust washers, lifters, valve springs and freeze plugs are replaced during rebuilding. - Every engine is tested on D&J’s RMC ETS-100 equipment for cylinder compression, oil system integrity and cooling system integrity before shipment. - Precision Plus adds ARP head studs and Tier 1 multi-layer steel head gaskets. - Precision Plus also includes an upgraded L5P oil cooler and a pinned oil pump drive gear. - Precision Plus ships with rocker assemblies, pushrods, valve bridges, rocker boxes, valve covers, an intake manifold, a harmonic balancer, a flywheel, a flex plate, a flex plate washer and new mounting hardware. - D&J estimates 19 hours of installation time for Precision Plus. - Essentials uses the same precision-machined block, keyed crankshaft and camshaft, upgraded L5P valve stem seals, new internal components and RMC testing. - Essentials uses Tier 1 head gaskets and is supplied ready for final assembly. - D&J estimates 25 hours of installation time for Essentials.

Between the lines: - The product split suggests D&J is targeting both performance-minded buyers and cost-conscious repair customers. - The more complete Precision Plus package reduces the number of parts that must move from the original engine, which should help streamline installs. - The Essentials package keeps the core machining and testing process but shifts more assembly work to the installer. - CEO Drew Pumphrey framed the launch as an extension of D&J’s Cummins program into the Duramax space.

What's next: - D&J plans to sell the two long blocks as replacement options for LML Duramax truck owners and repair shops. - The company is now positioned to build on its existing engine business with a new Chevrolet and GMC truck offering. - More distribution or installation details may follow as the product rollout continues.

The bottom line: - D&J is betting that a remanufactured, fully tested Duramax long block with clearer trim levels will appeal to owners who want a faster, more predictable engine replacement.