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Modular Head Shop 5.4L 1200+ HP Competition Rotating Assembly - Cobra Jet Crankshaft, Manley Pro Series I-Beam Rods, Diamond Competition Series Pistons, King XP Bearings

Available for 2V PI, 2V TFS, 3V and 4V applications.
Pricing: $3,299.00

Customize Your Item

- Select Block for Main Bearings -
 * required
- Select Bore Size -
 * required
- Select Dish Volume -
 * required
- Select Valve Reliefs -
 * required
- Add Ceramic Dome Coating -
 * required
- Add Lateral Gas Ports -
 * required
- Balance Rotating Assembly? -
 * required
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Modular Head Shop 5.4L 1200+ HP Competition Rotating Assembly 

  • Cobra Jet Forged 4130 Crankshaft - 4.165" Stroke
  • Diamond 5.4L Competition Series Pistons 
    • Full Round Style Forging 
    • Available in Standard, .010" or .020" Over Bore 
    • 1.330" Compression Distance -
      • approx .008" Piston to Deck Clearance with Stock Block 
    • .280" Down Top Ring Land 
    • Moly Coated Skirts
    • Includes 1.2mm x 1.5mm x 3.0mm Piston Ring Set 
      • Gas Nitrided Steel Top, Cast Iron 2nd, 3 Piece Oil
      • Excellent for power adder applications 
    • Trend .200" Wall H-13 Tool Steel Wrist Pins with Round Wire Locks 
  • Optional Piston Upgrades
    • Lateral Gas Ports - Suggested for 20lbs + Boost 
    • Ceramic Dome Coating - Thermal Barrier helps with piston fatigue  
  • Manley Pro Series Billet 4340 I-Beam Connecting Rods 
    • 100% American Made 
    • Standard Weight Version
    • 6.657" Length 
    • Supplied with 7/16" ARP 2000 Rod Bolts
    •  Approx weights:
      • Big End 454g
      • Pin End 225g
      • Total 725g
  • King XP Series Main Bearings - Select Iron or Aluminum Block 
  • King XP Series Rod Bearings 

This Diamond Competition Series Piston / Manley Pro Series Rod Combo is a great choice for any 5.4L based engine making anwhere in the 800 - 1400 HP range. This rotating assembly can be configured for 2V PI, 2V TFS, 3V and 4V cylinder head combinations. Please see the Compression Ratio chart for a full details. 

The Manley Pro Series I-Beams are one of the strongest available Connecting Rods for the 5.4L / 5.8L Engines. 100% American Made and machined from Billet 4340 vacuum degassed Steel. These rods have additional material around the connecting rod bolt area and are supplied with 7/16" ARP 2000 Rod Bolts. 

The Diamond Competition Series Pistons we use in this assembly are supplied with a Gas Nitrided Steel Top Ring Set and Trend .200" Wall Wrist Pins. The pistons are a full round forging with good piston ring spacing and are capable of handling 35lbs+ of boost with the supporting components included. 

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. We realize that not everyone wants or needs gas ports and for that reason it is optional. 

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. We will also cover any heavy metal they may need to be added to the crankshaft for balancing. 

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

Compression Ratios Calculated with a 3.620" x .036" Compression Thickness Head Gasket and a .008" Piston to deck clearance. 


2V TFS 38cc  2V PI 42cc  2V TFS 44cc  3V 50cc  4V 52cc 
-11.5cc Dish   12.9:1 12.1:1 11.8:1  10.9:1 10.6:1
-15.0cc Dish  12.2:1 11.5:1  11.2:1  10.4:1 10.1:1 
-20.0cc Dish 11.4:1 10.8:1 10.5:1 9.8:1 9.5:1 
-25.0cc Dish  10.6:1  10.1:1 9.9:1  9.2:1 9.0:1






Shipping Information

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

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