Engine Specifications: HP: 345 TQ: 400 Block: OE block 4 bolt main 1pc seal 1987-2000 Bore/Stroke: 4.040 x 3.480 Displacement: 350 Crankshaft: OE Reground external balance rear of crank/internal balance front of the crank Rods: OE powder metal 5.7” Pistons: Hypereutectic 9.1:1 compression Rings: Moly Camshaft: Hyd. roller Cam Specs: 220/224 @50 .495in/.502ex 110LSA Timing Chain: Double roller Cylinder Heads: ATK cast iron 76cc/165cc 1.94/1.50 Rocker Arms: Stamped steel 1.5 ratio Oil Pan: Rear sump 5qt (not for Chevelles with steering behind crossmember, some corvettes and 62-67 chevy II’s) Oil Pump: Melling high volume Recommended Components: Balancer: PowerBond internal balance 8” #PB1046-N Flexplate/Flywheel: Pioneer #FRA-159 external balance 168 tooth Intake Manifold: Weiand stealth dual plane #8150 Distributor: HEI (Iron gear) Water Pump: OE long pump Carburetor: Quick Fuel 680CFM vacuum secondary’s with electric choke #HR-680 Fuel Pump: Holley mechanical 110GPH #12-327-11 Spark Plugs: Champion #RV12C Spark Plug Wires: 8mm Engine Info: Oil: Conventional / Non synthetic 10W30 with Comp Cam zinc additive #159 for first 3000 miles Oil Filter: Wix or K and N per application Timing: 34-36 Degrees Spark Plug Gap: .035” Firing Order: 18436572 Octane: 91+ Stall Converter: 2200-2500 Exhaust: 1 5/8+ Headers Disclaimer: The parts listed are ATK’s recommendations of parts to be used to obtain our power figures listed. Power figures can vary based on parts used by the end user. It is the customer’s responsibility to verify components will work in their application. Some modifications to the vehicle may be required using these and or other aftermarket parts. . ATK reserves the right to substitute parts used in engines if necessary.
Highlights
- Block: New GM LT1/LT4
- Bore/Stroke: 4.065” x 3.622”
- Displacement (cu.in): 376 CID
- Crankshaft: Manley 4340 forged 58 tooth reluctor wheel
- Rods: Manley 4340 forged H beam 6.125” ARP 2000 bolts
Specifications
- Engine Displacement: 327 cu. in.
- Cylinder Head Material: Cast Iron
- Intake Manifold Included: No
- Oil Pan Included: Yes
- Timing Cover Included: No
- Harmonic Balancer Included: No
- Flexplate Included: No
- Flywheel Included: No
- Material Type: Cast Iron
- MFG. Part #: HP98
- Sold in Quantity: Each
- Brand: ATK Engines
Emissions Notice
Emissions warning: this part is for vehicle engine changes, not direct oem engine replacements. In California, engine changes are legal when done in compliance with California bureau of automotive repairs (bar) engine change policy. For assistance, call bar referee at: (800) 622-7733. And see https://bar.Ca.Gov/consumer/smog_check_program/engine_changes. All customers must comply with federal epa mobile source enforcement memorandum no. 1a (and addendum) and all applicable state regulations when conducting engine changes. Improper installation and/or use of this part in California may subject the installer and/or owner to a $37,500 penalty per violation per vehicle, revocation of registration, loss of use on California public right of ways, and proof of correction for tampering. There are similar restrictions and penalties under federal law and laws of all states for use of this engine change part on makes or models of vehicles that render them noncompliant with applicable state and/or federal emission laws with penalties under federal law of up to approximately $45,268 per tampered vehicle and/or engine






