Vital Specs: Dr. J’s 421 Chevy Small-Block
Block: Dart SHP
Bore: 4.155 inches
Stroke: 3.875 inches
CID: 421 cid
Compression Ratio: 11.5:1
Crankshaft: Callies Compstar
Camshaft: Isky Hyd Roller
Timing Chain: Cloyes
Lifters: Isky Hydraulic
Pushrods: Manley
Springs: Manley 22441-16
Installed Ht: 1.900
Spring Load, Closed: 170-pound seat
Spring Load, Open: 500 pounds at 1.100 inches
Retainer: Manley 10-degree Titanium
Valve Locks: Manley 10 degrees
Duration Intake: 258 degrees at 0.050
Intake Lift: 0.640 inch
Duration Exhaust: 262 degrees at 0.050
Exhaust Lift: 0.640 inch
Rockers: COMP Cams
Rocker Ratio: 1.6:1
Lobe Separation: 108 degrees
Installed Centerline: 105 degrees
Ring Pack: CP 1.5/1.5/3 mm
Ring Endgap: 0.020 Top/0.025 Second
Piston: CP bullet Pistons
Piston Clearance: 0.005
Main Fasteners: ARP/Dart
Rods: Callies Compstar 6.00 H-Beam
Main Bearings: Clevite H
Rod Bearings: Clevite HN
Main Journal Diameter: 2.49 inches
Rod Journal Diameter: 2.100 inches
Main Clearance: 0.003 inch
Rod Clearance: 0.003 inch
Cylinder Heads: AirWolf 220
Chamber Volume 67 cc
Head Fasteners: ARP Custom Studs
Intake Manifold: Dr. J’s Performance Hurricane
Intake Port Flow: 325 cfm at 0.700
Exhaust Port Flow: 244 cfm at 0.700
Intake Valve: Manley 2.125
Exhaust Valve: Manley 1.600
Cylinder Head Gaskets: Fel-Pro 1144 (0.041 inch)
Piston/Head Clearance: 0.040 inch
Engine Gaskets: Fel-Pro 1206
Carburetor 950-cfm Holley Street HP
Carb Spacer HVH
Header: Schoenfeld
Coil MSD Ignition
Ignition MSD Ignition
Spark Plug Wires: MSD Ignition
Damper: Professional Products
Water Pump: Meziere Electric
Oil Pan: Moroso Oil Pan
Oil Pump: Melling M55a
Oil: Dello 400 30w