Description: 

• HP & Torque: 491 HP / 509 FT LBS
• Compression Ratio: 10.4:1
• Aluminum Heads
• Hydraulic Roller Cam
• Forged Crank
• Forged Pistons

Block:

• NEW BluePrint Cast Iron Block
• Manufactured and Machined in the USA!
• Align honed main bearing bore
• Cylinders honed on computer-controlled machine to within .0002 straightness and roundness
• Cylinders are sonic tested for thickness
• 4-Bolt Main
• 4.000" Bore
• 1-Piece Rear Main Seal
• Mech fuel pump provision: Yes
• Passenger Side Dipstick
• Drilled and tapped for clutch linkage

Rotating Assembly:

• New BluePrint Forged Crankshaft
• 3.875 " Stroke
• Forged I-beam 6.000" connecting rods
• Forged Pistons
• Internal Front/ External Rear

Cylinder Heads:

• BluePrint Aluminum Cylinder Heads - HP8103
• 64cc chamber
• 2.08" intake/1.60" exhaust valves
• 220cc intake/67cc exhaust runners

Cam Specs:

• Cam Type: Roller
• .544 Intake .555 Exhaust
• 230 Intake / 236 Exhaust duration
• @ .050, 110 ° lobe separation angle

Ignition Timing:

• 34 degrees total at 3500 RPM

Also includes:

• Valve covers, oil pan and timing cover

Notes: 

• *A bronze distributor gear is NOT recommended on this engine
• Not for use in pollution-controlled vehicles.
• This engine features a true 4-inch bore, which mathematically yields 389 CID with a 3.875-inch stroke.
• 93 octane or higher is recommended for this engine. 
• The performance aluminum cylinder heads on this engine feature a .500 raised port vs OEM.