Type: LS3 6.8L
Displacement: 416 Cubic Inches
Compression Ratio: 11.2:1
Bore x Stroke: 4.065 x 4.000
Rev Limit: 7000 RPM
Crank: Callies Forged
Rods: Callies H-Beam
Pistons: Mahle Motorsports
Cam: Mast Custom 3-Bolt Core Cam
Intake: Not Included
Valve Springs: PAC Racing Dual Springs
*All hp numbers will be within 2% of the advertised number.
Mast Motorsports Handbuilt LS engines feature the best components and are assembled by professional machinist. All handbuilt engines feature ARP Main Studs, ARP Head Bolts and a balanced and blueprinted block.
The 550 Performance Street Long Block’s heart and soul is the new 4.065 aluminum block. It has a Mast Motorsports engineered camshaft that is custom ground on a Mast Motorsports billet cam core. The 416 foundation is a honed and decked LS3 aluminum block with a 4.000” forged Callies rotating assembly with Mahle pistons that is topped off with Mast Custom Cast cylinder heads. ARP fasteners are used throughout and Mast pushrods ride on LS7 hydraulic roller lifters. The 550 Performance Street Long Block is the first release of a diverse line of Mast Motorsports hand built LS3 based long blocks that are designed for the Hot Rod/Muscle Car market. The 550 Performance Street Long Block peaks at the 550+ horsepower mark and is competitively priced for such a powerful complete long block.