(1) Complete Assembled Aluminum Cylinder Head.
(12) ARP Head Bolts
(12) Harland Sharp Bolt down True Roller Rocker Arms and Bolts.
(1 ) Edelbrock Head Gasket
(12) Comp Cams Hardended Pushrod Set
(1 ) Intake and Exhaust Header Gasket Edelbrock
This Top End Package matched up with a 4.6 or 4.7 Jeep Stroker Short Block Assembly can yield 100+ Morse Horsepower and Torque over the Factory engine. That’s V8 Power in a Six Cylinder Package. Designed with 1991-2006 4.0L intake port locations and must be used with 1991-2006 intake manifold. 1991-98 4.0L exhaust port locations and must be used with 1991-98 factory header or aftermarket exhaust header. This cylinder head will also fit 1976-90 AMC 4.2L engines with no modification to the water jacket and the appropriate intake manifold and header combination.
This cylinder head is pending 50-state emission legal for 4.0L engines when used with factory Fuel Injection components. It’s also pending 50-state emission legal for 4.2L engines when used with a Mopar Fuel Injection Conversion Kit (E.O. Number D-265-21).Lightweight. Big gain in Torque an Horses!!
- Combustion chamber volume: 55cc
- Intake runner volume: 144cc
- Exhaust runner volume: 77cc
- Intake valve diameter: 1.91″
- Exhaust valve diameter: 1.50″
- Valve stem diameter: 5/16″
- Valve guides: Manganese bronze
- Deck thickness: .750″
- Valve spring diameter: 1.26″
- Valve spring maximum lift: .540″
- Rocker stud: N/A
- Guideplate: N/A
- Pushrod diameter: N/A
- Valve angle: 10° (stock)
- Exhaust port location: Stock (1991-98)
- Spark plug fitment: 14mm x 3/4 reach, gasket seat
Harland Sharp 1.6 to 1 Ratio. Bolt On Rockers
Comp Cams 9.600 Hardened Pushrods
Edelbrock MLS Head Gasket and Intake and Exhaust Gasket
INSTALLATION NOTE: Recommended spark plugs: Champion RC12YC or equivalent 14mm x 3/4″ reach with flat gasket seat. Recommended gasket for 4.0L: Edelbrock #7348 or Fel-Pro #26211PT. Deck thickness: 3/4″.
Must be used with 1991-2006 intake manifolds and 1991-98 factory or aftermarket exhaust manifolds, which will require modification to exhaust systems on applications other than 1991-1998.
The old saying goes, “There’s no replacement for displacement.” Darn few single mods you can make to the 4.0L will give you more than a handful of ponies or pound-feet. One of them is to increase the displacement via an increase in stroke. Engine gurus have commented that, while stroking an engine is not to be taken lightly, it ain’t brain surgery on the 4.0L.
Like most modern engines, the 4.0L (bore and stroke: 3.88 x 3.44 inches) is oversquare, meaning the bore dimension is larger than the stroke. The 258ci (4.2L) Jeep six (3.75 x 3.89-inch) used before the 4.0L was undersquare, meaning the bore dimension is smaller than the stroke. Generally speaking, the oversquare engine is decent at low rpm, most efficient in the middle rpm range and has good high-rpm performance. The undersquare, long-stroke engine produces the best low-end torque, has a good midrange, but is so-so on the upper end.