Overview Simplify engine building and save time with pre-engineered, dyno tested short block combinations from Dart's SHP (Special High Performance) group. These quality component packages are designed to allow the user to build more powerful and durable engines at a very affordable cost. Compression Ratios: 10.5:1 with 72cc chamber heads and flat top pistons. 11.4:1 with 64cc chamber heads and flat top pistons. 9.25:1 with 72cc chamber heads and 20cc dish pistons. 10.0:1 with 64cc chamber heads and 20cc dish pistons. Features: Built on Dart's powerful SHP block for excellent reliability. 4.125 bore and 3.480 stroke. Internally balanced rotating assembly. Plate honed cylinder bores. Forged 4340 steel crankshaft. Forged 4340 I-Beam Rods w/ 3/8“ Cap Screws. Hypereutectic Flat Top Pistons w/ Full Floating Pin Hastings Moly rings. Clevite bearings. Coated cam bearings for added durability. Upgrades Available: Forged 4340 Crank, H-Beam Rods & Forged Pistons.