Coolant washdown from deteriorated lower intake manifold land gaskets ruins connecting rod bearings in transport vehicles. The Chevrolet 12491872 3.4L 207ci Remanufactured Long Block cures fluid contamination across this commercial long block repower. This 6-Cylinder 160HP pushrod motor requires thorough oil gallery flush procedures before installing the front engine accessory bracket assembly.

High-density ASTM A48 Class 35 gray cast iron forms the monolithic 60-degree V6 cylinder block paired with iron heads. A balanced nodular iron crankshaft spins in tri-metal copper-lead bearings secured by two-bolt main bearing caps. This Chevrolet engine core demands a 12V 150A starter draw during cold shop starts. Total dry weight is 310 lbs, measuring 24in length, 23in width, 25in height, with a 4.5 quarts oil capacity.

Key Features of Chevrolet 12491872

Fleet repair managers buy Chevrolet 12491872 Remanufactured Long Block units to restore reliable service delivery schedules. Every industrial engine rebuild integrates diamond-machined intake sealing surfaces to permanently stop coolant migration.

- Cylinder bores measure 3.622in with diamond plateau hone surface finishes.
- Main bearing journal clearance holds at 0.0014in across the rotating assembly.
- Hydraulic roller lifters minimize friction across induction-hardened camshaft lobes.
- Reinforced multi layer steel head gaskets eliminate cylinder deck compression leakage.
- Induction-hardened valve seat inserts resist unleaded gasoline recession wear.
- This 12491872 commercial core features precision deck resurfacing flat within 0.0003in.
- Connecting rod assemblies balance within two grams across all journals.

Brake Dyno Performance Records

Controlled brake cell testing verifies that this 12491872 long block engine outputs 160 continuous BHP and 200 ft-lbs of torque at 3600 continuous load RPM. Internal oil gallery pressure measures 52 PSI while oil sump temp levels at 192°F under sustained brake loading. Exhaust gas temp tops at 1260°F down the test header runners. Cylinder compression tests between 172 PSI and 180 PSI across all chambers. Crankshaft center journal runout holds within 0.0003in TIR.

Field Installation Operational Limits

Transmission kickdown linkages need 5 lbs of linear pull force to guarantee positive downshift response under load. This pushrod motor is not designed for twin-turbo competition applications, marine jet drives, or stationary power generation skids.

- Drain initial break-in petroleum motor oil after 500 miles or 25 operating hours.
- Check non-adjustable hydraulic roller lifter preload at 0.020in to 0.040in cold.
- Torque cylinder head fasteners to 37 ft-lbs plus 90 degrees rotation.

Commercial Protection Package Contents

Backed by the standard Chevrolet assembly standard, this remanufactured long block carries a 3-Year 100,000-mile parts warranty. The wood shipping crate contains the long block engine, oil pan, front timing cover, stamped valve covers, oil pickup tube, and signed dyno load sheet.