388 LS3/LS7 4.125 X 3.622' BILLET-

CNC-Motorsports LS Dart short blocks are high-quality, custom-built, 100% machined, CNC machined, and blue-printed to race-winning specs. Features: Dart SHP LS Next Cast Iron Block (4.125 bore), Callies Compstar 4340 forged steel crankshaft (3.625 Stroke), Callies Compstar H-Beam connecting rods, and Diamond LS2K forged pistons. Designed to fit all 12-degree LS Heads (L92 type). Rated to support 1500 HP with extreme duty rod upgrade, 1800 HP with aluminum rod and pro block upgrade. Compression Ratio: 10.9:1 (62cc head, Turbo/Nitrous), 10.0:1 (70cc head, Turbo/Nitrous). Camshaft & timing chain not included. SHP Pro block upgrade includes ARP main studs.