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Diamond 5.8L GT500 Series Piston / Molnar PWR ADR H-Beam Connecting Rod Combo

Pricing: $1,599.00

Customize Your Item

- Select Piston Bore / Volume -
 * required
- Select Wrist Pins -
 * required
- Add Ceramic Dome Coating? -
- Add Lateral Gas Ports -
 * required
- Send in Crankshaft for Balancing -
 * required
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  • Diamond 5.8L GT500 Series Pistons 
    • Full Round Style Forging 
    • 1.315" Compression Distance 
    • .320" Down Top Ring Land 
    • Moly Coated Skirts 
    • .151" Intake, .050" Exhaust Valve Reliefs - Will accommodate +1mm Valves 
    • Forced Pin Oiling 
    • .180" Wall 8620 Alloy Wrist Pins 
    • 1.2mm x 1.5mm x 3.0mm Ring AP Steel Top, Napier 2nd Ring Set
  • Optional Upgrades
    • Lateral Gas Ports - Suggested for 20lbs + Boost 
    • .200" H-13 Tool Steel Pins - Suggested for 800 HP +
    • Ceramic Dome Coating - Thermal Barrier helps with piston fatigue  
  • Molnar 5.4L / 5.8L PWR ADR Connecting Rods 
    • Forged 4340 H-Beam Design 
    • 6.657" Length 
    • Supplied with 7/16" ARP 2000 Rod Bolts
    •  Approx weights:
      • Big End 487g
      • Pin End 207g
      • Total 694g

This Diamond Piston / Molnar Connecting Rod Combo for the 5.8L GT500 is an excellent choice when looking to upgrade the bottom end components. Whether you are looking to hold 800 HP reliably, or looking to get close to the 1400 HP mark, this kit has the best components for the price. 

The Pistons included are from the Diamond 5.8L GT500 Series. These are built for boost. Forged from 2618 Alloy Aluminum, they are supplied with a very nice Total Seal AP Steel Ring Set and premium 8620 Alloy Wrist Pins. The Piston Ring set includes a Napier 2nd Ring, which helps with oil control. Pistons are available in the standard 5.8L Plasma Arc 3.681" Bore, as well as 3.650" and 3.670" Bore for blocks that have been sleeved. Our recommendation for sleeved applications is to start with a 3.650" bore. This gives you some extra material for future rebuilds. Available in 8.5:1, 9.0:1, 9.5:1, 10.0:1 and 10.5:1 Compression Ratios. 

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. 

While you will not break a .180" Wall 8620 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 8620 or 4130 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. 

If you would like to send in your crankshaft, we can balance the rotating assembly for you. The cost for balancing is $350.00 and includes any heavy metal needed for balancing. It will also cover the outbound freight. 

The Pistons in this kit are not always in stock. Please allow around 3 weeks for delivery. If you are in a rush, please check with us for availability before placing your order. 


Shipping Information

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

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