ATK Engines High-Performance Small Block Chevy 350ci Crate Engine – 390 HP / 420 TQ
Free Shipping$3,429.00
Mid Dress Engine
High-Performance Crate Engine
- Small Block Chevy 350 ci.
- 375 HP/420 ft.-lbs. TQ
- Mid Dress Engine Includes:
- Base Engine Build
- Intake Manifold
- Distributor
- Water Pump
- Harmonic Balancer
- Flex Plate
Did you like this product? Add to favorites now and follow the product.
Confirm your vehicle, VIN and application before ordering. Call (478) 379-2400 or ask about fitment.
Shipping details | Returns & refunds
Description
Engine Specifications:
- Horsepower: 390
- Torque: 420
- Block: 1996-2000 OE roller block 4-bolt main 1-piece seal
- Bore/Stroke: 4.040 in. x 3.480 in.
- Displacement: 350 ci
- Crankshaft: OE Reground external balance rear of the crank/internal balance front of the crank
- Rods: OE powder metal 5.700 in.
- Pistons: Hypereutectic 10:1 Compression
- Rings: Moly
- Camshaft: Hyd. Roller
- Cam Specs: 220/224 @ 50 .528in/.536ex 110 LSA
- Timing Chain: Double Roller
- Cylinder Heads: ATK High-Performance aluminum with 2.020 in. /1.600 ex. valves
- Rocker Arms: Billet aluminum roller rockers 1.6 ratio
- Oil Pan: Rear sump 5qt (not for Chevelles with steering behind crossmember, some Corvettes, and 1962-2967 Chevy II’s)
- Oil Pump: Melling STD Volume
- Flexplate/Flywheel: Externally Balanced – Pioneer #FRA-159
- Balancer: Internally Balanced – PowerBond #PB1046-N
- Intake Manifold: ATK dual plane intake
- Distributor: HEI (Iron Gear)
- Water Pump: OE long pump
Recommended Components:
- Carburetor: Quick Fuel 680CFM Vacuum secondary’s electric choke #HR-680
- Fuel Pump: Holley mechanical 110GPH #12-327-11
- Spark Plugs: Autolite #3923
- Spark Plug Wires: 8 mm
Engine Info:
- Oil: Conventional / Non Synthetic 10W30
- Oil Filter: Wix or K&N
- Timing: 34-36 Degrees
- Spark Plug Gap: .035 in.
- Firing Order: 18436572
- Octane: 91+
- Stall Converter: 2200-2800
- Exhaust: 1 5/8 in. Headers
Disclaimer: Verify compatibility before installation. Vehicle modifications may be required.
Emissions Note:
This part is only legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles or on vehicles used solely for the purposes of closed competition racing.
| Part Type | Engine |
|---|---|
| Product Line | ATK HP Crate Engines Small Block Chevy 350 ci / 390 HP / 420 FT.-LBS. |
| Cylinder Head Material | Aluminum |
| Engine Block Material | Cast iron |
| Engine Displacement | 350 ci. |
| Engine Make/Size | Chevy Small Block |
| Engine Type | High-Performance Crate Engine |
| Package Depth | 37.00 |
| Package Height | 40.00 |
| Package Width | 27.00 |
| Part Category | Performance Parts |
| Part Fitment | Semi Universal |
| Quantity | Sold individually |
| Shipping Weight | 385.00 |
| Vendor Part Number | HP89M |
Use or break-in oil or conventional (non-synthetic) 10w30 oil with zinc additive for the first 500 miles of operation. Do not drive for long periods at any single speed, always vary your speed. Do not tow a trailer or put other heavy loads on the vehicle. It is best to avoid long periods of idling during this period. Check the engine oil and coolant levels daily.
Engines with flat tappet hydraulic cams only - Run the engine between 2,000 and 2,500 RPM\\\'s, with no-load on the engine for the first 30 minutes. Let the engine cool down completely and repeat process 2-3 more times. Do not idle the engine for any extended period at this time, this is critical to break in the camshaft.
At 500 Miles change the engine oil and filter using conventional (non-synthetic) oil with a zinc additive. Check fuel and ignition settings, adjust valves (where applicable). Drive the next 500 miles normally, without high RPM\\\'s (below 5000 RPM), hard use, or extended periods of high loading or long periods of idling.
Change the oil and oil filter again at 1,000 miles. Continue using conventional (non-synthetic) oils and zinc additive, until about 4,000 miles. At that point, you may run a quality 10w30 synthetic oil if you choose. Use of oil with zinc or a zinc additive for the life of your engine is recommended.
Related products
PrimeCore Engines & Parts
Quality remanufactured, rebuilt and performance engines shipped from Madison, Georgia.
3729 Hestertown Road NE, Madison, GA 30650
Copyright 2026 PrimeCore Engines. All rights reserved.
Reviews
There are no reviews yet.