| Engine Type | | In-Line-6 |
| Displacement | 4.2 L | 256 cu inch |
| RPO (VIN Code) | LL8 | |
| Spark Plug Gap | Maximum | 0.050 inch |
| Minimum | 0.044 inch |
| Bore | 3.66 inch |
| Stroke | 4.02 inch |
| Compression Ratio | | 10: 1 |
| Firing Order | | 1-5-3-6-2-4 |
| Oil Pressure (At the sending unit) Warm - Minimum | | 12 psi - 1200 RPM |
| Cylinder Bore | Diameter | 3.6638-3.6644 inch |
| Out Of Round - Maximum | 0.0005 inch |
| Cylinder Liner Recession - Maximum | 0.0006 inch |
| Piston & Pin | Piston Diameter - (1.4961 inch) down from top | 3.6627-3.6633 inch |
| Piston to Bore Clearance | 0.0004-0.0017 inch |
| Piston to Pin Clearance | 0.00012-0.0005 inch |
| Pin Bore | 0.9056-0.9058 inch |
| Piston Pin Diameter | 0.9054-0.9055 inch |
| Piston Ring | Top Groove to Ring Side Clearance | 0 0017-0.0037 inch |
| Second Groove to Ring Side Clearance | 0.0017-0.0037 inch |
| Oil Control Groove to Ring Side Clearance | 0.0023-0.0085 inch |
| Top Ring Gap - (3.66 inch) down from top of cylinder | 0 0079-0.0157 inch |
| Second Ring Gap - (3.66 inch) down from top of cylinder | 0.0118-0.0197 inch |
| Oil Control Ring Gap- (3.66 inch) down from top of cylinder | 0.0098-0.0299 inch |
| Crankshaft | Main Journal Diameter | 2.7567-2.7574 inch |
| Main Journal Taper - Maximum | 0.0002 inch |
| Out Of Round - Maximum | 0.0002 inch |
| Cylinder Block Main Bearing Bore Diameter | 3.0760-3.0766 inch |
| Crankshaft Main Bearing Inside Diameter | 2.7579-2.7592 inch |
| Main Bearing Clearance | 0.0004-0.0025 inch |
| Crankshaft End Play | 0.0044-0.0153 inch |
| Connecting Rod | Connecting Rod Bearing Journal Diameter | 2.2337-2.2342 inch |
| Connecting Rod Bearing Journal Out Of Round - Maximum | 0.0002 inch |
| Connecting Rod Bearing Bore Diameter | 2.3749-2.3755 inch |
| Connecting Rod Inside Bearing Diameter | 2.2351-2.2362 inch |
| Connecting Rod Bearing Journal Clearance | 0.0008-0.0025 inch |
| Connecting Rod Side Clearance | 0.0019-0.0137 inch |
| Connecting Rod Bushing to Pin Clearance | 0.0004-0.0007 inch |
| Connecting Rod Inside Bushing Diameter | 0.9055-0.9060 inch |
| Camshaft | Journal Diameter-All Intake and Exhaust #2 - #7 | 1.0612-1.0622 inch |
| Journal Diameter - Exhaust #1 | 1.1794-1.1804 inch |
| Camshaft Bore Diameter - All Intake and Exhaust #2 - #7 | 1.0638-1.0646 inch |
| Camshaft Bore Diameter-Exhaust #1 | 1.1820-1.1828 inch |
| Journal Clearance | 0.0015-0.0033 inch |
| Camshaft Endplay- Intake | 0.0020-0.0079 inch |
| Camshaft Endplay - Exhaust | 0.0017-0.0084 inch |
| Valve System | Stationary Lash Adjuster | Hydraulic |
| Valve Seat Runout - Maximum | 0.002 inch |
| Valve Face Runout - Maximum | 0.0015 inch |
| Valve Stem Clearance - Intake | 0.0011-0.0025 inch |
| Valve Stem Clearance - Exhaust | 0.0015-0.0030 inch |
| Valve Spring | Valve Springs Load (Closed) | 47.5-52.5 lb @ 1.701 inch |
| Valve Springs Load (Open) | 130-142 lb @ 1.260 inch |
| Oil Pump | Gear Pocket Depth | 0.615-0.614 inch |
| Gear Pocket Diameter | 3.430-3.429 inch |
| Oil Pump Drive Gear | Outer Diameter Tolerance | 2.893-2.891 inch |
| Width | 0.613-0.611 inch |
| Oil Pump Driven Gear | Outer Diameter Tolerance | 3.428-3.426 inch |
| Width | 0.605-0.611 inch |
| Lobe Inner Diameter - Maximum | 0.469 inch |
| Oil Pump Gear | Valve to Bore Clearance | 0.575-0.574 inch |