Engine Parts 3.8L 232cui & 4.2L 258 cui Jeep CJ7
Replacement parts for the AMC 232 and 258 cui inline-sixes (1976-1986) – from valve to oil pan.
Why the AMC Inline-Sixes in the Jeep CJ7 Deserve a Full Overhaul Today.
The 232 and its bigger brother, the 258 cui, are among the toughest engines ever fitted to a CJ: seven main bearings, a cast-iron block with plenty of material in reserve, and a torque curve that pushes the Jeep through terrain rather than revving through it. That very toughness tempts owners to ignore wear for too long. After forty years the timing chain has stretched and lets the valve timing drift, valve seats and stems are pounded out, and the hydraulic lifters rattle on a cold start. The notorious plastic valve cover of the later years warps and weeps oil onto the manifold, the cork oil pan gasket has lost its elasticity, and worn motor mounts let the heavy block work against the frame. Overhaul the six properly once and it will run for decades more.
From Valve Seat to Oil Pan: How to Bring the Six Back to Life
- Gaskets and gasket sets: The cylinder head gasket for both displacements, upper and lower sets individually or as a complete engine gasket set, plus manifold, water pump, thermostat and fuel pump gaskets.
- Valve train: Intake and exhaust valves in standard and .015" oversize, matching valve seats, valve stem seals, rocker arm pivots and hydraulic lifters for the complete head.
- Valve covers, crankcase ventilation and exhaust side: Valve covers in plastic or as an aluminium set with 4.2L logo, the matching gaskets for steel, plastic and aluminium covers, PCV valves by model year, the EGR valve and the exhaust manifold set including gaskets.
- Pistons, rings and bearing shells: Piston sets for the 4.2L in standard, .030" and .060", piston ring sets for both displacements, rod bearings up to .030" oversize and crankshaft main bearings along with camshaft bearings.
- Timing and crankshaft: The three-piece timing set with guide and cover, the camshaft for the 4.2L, front and rear crankshaft seals plus the crankshaft harmonic balancer.
- Oil circuit and engine mounting: Oil pans with or without gasket, oil pumps for early and late model years, filters and drain plugs, plus motor mounts for left and right and complete polyurethane bushing kits.
Where American Suppliers Set the Standard.
Crown Automotive covers the largest share of the range – from gaskets through oil pans to valve covers, all to OEM specification. Enginetech contributes timing sets, pistons and gasket kits, Sealed Power the valves, pistons and every bearing shell; both stand for classic American engine building. Dorman supplies small parts, Standard Ignition the PCV valves, Omix and RT Off-Road the valve covers, Walker Exhaust the converter gasket. The polyurethane bushing kits come from Prothane in California, long established as the durable alternative to stock rubber.
Advice on Oversizes, Torque Figures and the Right Valve Cover.
With the 4.2L in particular, the model year decides the parts: steel, plastic and aluminium valve covers each need their own gasket, and PCV valves change from year to year. Tell us the year and version and we will put the right combination together, give you torque figures for head and rods, and work out the oversize you need after machining. Most items ship from stock in Germany within the next business day.