Home - Return to Previous Page
Click on image to zoom

Modular Head Shop 5.4L 1000+ HP Rotating Assembly - Cobra Jet Crankshaft, K1 H-Beam Rods, JE FSR Pistons, King XP Bearings

Designed for 2V, 3V and 4V Applications.
Pricing: $2,249.00

Customize Your Item

- Select Block for Main Bearings -
 * required
- Select Cylinder Head Style -
 * required
- Select Piston Bore -
 * required
- Select Compression Ratio -
 * required
- Select Wrist Pins -
 * required
- Balance Rotating Assembly? -
 * required
Free Shipping!


Modular Head Shop 5.4L 1000+ HP Rotating Assembly 

  • Cobra Jet Forged 4130 Crankshaft - 4.165" Stroke
  • JE FSR Pistons 
    • Forged Side Relief Design - 2618 Alloy 
    • 1.320" Compression Distance 
    • .300" Down Top Ring Land 
    •  2V, 3V or 4V Specific 
    • .150" Wall 5115 Alloy Steel Wrist Pins
    • JE Pro Steel Piston Ring Set 
  • Optional Piston Upgrades
    • Lateral Gas Ports - Suggested for 20lbs + Boost 
    • .170" H-13 Tool Steel Pins - Suggested for 800 HP +
    • Ceramic Dome Coating - Thermal Barrier helps with piston fatigue  
  • K1 5.4L / 5.8L Connecting Rods 
    • Forged 4340 H-Beam Design 
    • 6.657" Length 
    • Supplied with 7/16" ARP 2000 Rod Bolts
    •  Approx weights:
      • Big End 454g
      • Pin End 180g
      • Total 634g
  • King XP Series Main Bearings - Please select 5.4L Iron or Aluminum 
  • King XP Series Rod Bearings 

Pistons are available in configurations for 2V, 4V and 4V Cylinder Heads. They are listed by Compression Ratio using the stock deck height and head gasket dimensions. Available Compression Ratios are 8.5:1, 9.5:1 and 11.0:1 for each Cylinder Head design. Please see the Compression Ratios tab for dish volumes and specifics.  

This 5.4L Rotating Assembly is an excellent choice for 2V, 3V or 4V applications up to 1100-1200 WHP. 
Excellent for all Lightning and 5.4L GT500 applications. 

Both the K1 H-Beam Rods and JE FSR Pistons offer some good weight savings in comparison to some of the other options. The JE Pistons supplied in this kit come with a raised Compression Height of 1.320", bringing the crown of the piston closer to the top of the deck. This helps with combustion efficiency and overall power production. The Pistons also come standard with JE's Pefect Skirt Coating which helps with friction and skirt rock. The K1 H-Beam Rods are an excellent design and come with 7/16" ARP 2000 Bolts. These components complement each other very well and that is why we have used them together in so many builds. 

While you will not break the standard .150" Wall 5115 Alloy Pin at 800 HP or even 1000 HP, we suggest the H-13 Tool Steel Wrist Pin upgrade at 800 HP for one reason...rigidity. The H-13 Pins are more rigid. We have seen plenty of wrist pin flex around the 800-900 HP mark with standard alloy pins. The flexing wrist pin will gall up the pin bores of the piston and damage the pin bushing in the connecting rods. This simply shortens the life of both components. 

Optional Lateral Gas Ports are suggested for boost levels over 20lbs. The gas ports allow combustion gasses behind the top ring, pushing it out harder against the cylinder walls for better sealing. 

This assembly will come un-balanced unless that option is selected. There is no option for not balancing an assembly. It MUST be professionally balanced either by us or another machine shop. 
It is recommended to have us balance the assembly in house as we pay very close attention to details to get you the most accurately balanced crankshaft possible. 

The Pistons in this kit are not always in stock. Please allow around 4 weeks for delivery. Add 7-business days for balancing option as the pistons must come here first. If you are in a rush, please check with us for availability before placing your order. 

Compression Ratios / Dish Size

       Compression Ratios are calculated with a stock deck height and stock cylinder head gasket dimensions. These Pistons use a 1.320" Compression Height which leaves approx .020" Piston to deck clearance on a stock deck. Cylinder Head Gasket dimensions used are 3.620" x .036" 

         2V PI - 42cc Chamber 

  8.5:1   9.5:1  11.0:1 
3.552"  -38.30 -27.70 -15.80
3.652"  -38.50  -28.00 -16.10
3.572"  -39.20  -28.50 -16.40

        3V - 50cc Chamber
MHS CNC Chambers are 53cc and will drop the advertised compression ratio 
by approx. 0.2 of a point. Example: 9.5:1 down to 9.3:1 

  8.5:1   9.5:1  11.0:1 
3.552"  -30.30 -19.70 -7.80
3.652"  -30.80  -20.10 -8.10
3.572"  -31.20 -20.50 -8.40

 4V - 52cc Chamber - All 4V's have 52cc Chambers stock. 
MHS CNC Chambers are approx. 53.5cc and will drop the advertised compression ratio 
by approx. 0.15 of a point. Example: 9.5:1 down to 9.35:1 

4V 8.5:1   9.5:1  11.0:1 
3.552"  -27.70 -17.10 -5.20
3.652"  -28.20  -17.50 -5.50
3.572"  -28.60 -17.90 -5.80




Shipping Information

  • Item Requires Shipping
  • 35.0 lbs.
  • W14.0000” x H14.0000” x L28.0000”
  • Free Shipping!

Customer Reviews

Comment Total Reviews (0)

Write the First Review!

You must login to post a review.