- Engines & Components
- Engine - Assembled / Ready-to-Run
- ATK HP Long Block Crate Engines for GM LS 5.3L Vehicles
High-Performance Replacement Engine for LS-Based Trucks, Vans & SUV's
In 2007, ATK launched a High-Performance Division with one of the finest engine shops in the country. By reverse engineering all of their engines, they are able to eliminate any OEM deficiencies. This makes an ATK built crate engine have a superior design over the original engine by incorporating better components when needed. These quality built engines are offered in three different stages for ease of finishing an engine swap. ATK HP engines feature a 24 month/unlimited mile warranty.
Show More
Engine Specifications
This engine was designed to be a performance upgrade for LS based vehicles or perfect for a swap in a hot rod. For optimal performance you will need headers, chassis dyno tune, and upgraded injectors.
- Horsepower: 385 hp
- Torque: 390 lb/ft
Block Information:
- OE LM7/5.3L iron
- Bore/Stroke: 3.809" x 3.622"
- Displacement: 5.3L
Rotating Assembly:
- Crankshaft: OE GM 24 tooth reluctor wheel
- Rods: Stock GM
- Compression Ratio: 9.5:1
- Pistons: Hypereutectic
- Rings: Moly
Camshaft Specs:
- Camshaft: Hydraulic roller
- Cam Specs: Custom performance grind
Cylinder Head Information:
- Cylinder Heads: OE aluminum
- Combustion Chamber: 61.15cc
- Valve Size: 1.89" Intake / 1.55" Exhaust
- Rocker Arms: OE roller rockers 1.7 ratio
Oil Pump Information:
- Oil Pump: Melling standard volume
Base Engine Includes:
- Short Block
- Camshaft
- Timing Set
- Cylinder Heads
- Oil Pump