Cracking and popping from no mufflers, we ran the motor for the required 30-minute break-in period, keeping a close eye for leaks, oil pressure and loose appendages. As our motor was outfitted with a roller cam, no cam break-in is necessary, however the traditional bearing and ring break-in still applies. We know you're anxious, but the first 10-12 hours of run time is most crucial to your engines' long-term life. So, order, install and enjoy!
GM Performance Parts ZZ383Peak hp: 425 hp at 5,500 rpmPeak tq: 460 ft.lb. at 4,500 rpmDisplacement: 383 inchesBore x Stroke: 4.005x3.80 inchesCompression Ratio: 9.1:1Block: Cast iron, four-bolt intermediate mains Heads: Aluminum Fast-BurnValves (intake/exhaust)- 2.00/1.55 inchesChamber volume- 62 ccCrankshaft: 4340 forged steel alloyConnecting Rods: 5.7-inch forged powered-metalPistons: hypereutectic aluminumCamshaft: hydraulic rollerLift- .509 inches intake/.528 inches exhaustDuration: 222 degrees intake/230 degrees exhaust at .050 lift
Rocker Arm Ratio: 1.5:1 aluminum roller rocker armTiming Chain: 8mm single roller designOil Pan: 5-quart stamped steelOil Filter: AC Delco part # PF25Maximum rpm: 6,000 rpmSpark Plugs: R44LTSSpark Timing: 32 degrees maximum at 4,000 rpm with vacuum adv. disconnected GM HEI billet distributorZoops PulleysBillet 5-rib serpentine pulleysOutboard alternator mountRemote type II power steeringMeziere Mechanical Water PumpPolished billet aluminum reverse rotation pump- PN WPR401UPU.S. Radiator PN 010690Chevel-Mal V-8 2 5/8x1 1/2-inch triple flowHolley 4150 750-cfm vacuum secondary carburetorHolley 65-gpm mechanical fuel pumpPowermaster 100 amp alternator- PN 27294Powermaster mastertorque starter- PN 9600Flex-A-Lite dual electric fan- PN 210Proform genuine GM aluminum valve covers- PN 141-132