Dart's new Special High Performance (SHP) small-block meets the need for an affordable, precision-machined cast-iron block with superior features. Designed for high-performance and heavy-duty applications producing up to 600 hp, the SHP block is the ideal starting point for circle track competitors, hot rodders, drag racers, off-roaders, and high-performance marine enthusiasts. Two part numbers cover the vast majority of small-block engine combinations: 31161111 (4.00-inch bore) and 31161211 (4.125-inch bore).
Made in the USA on all-new tooling, the SHP block delivers exceptional value. Priced hundreds of dollars less than a full-race block, the SHP block eliminates the time and expense of rebuilding a junkyard core. The SHP block is tailored to the most popular performance and racing applications, with 350 main bearings and a choice of 4.00-inch and 4.125-inch cylinder bores.
SHP blocks are manufactured on Dart's in-house CNC machining centers to precision tolerances. The SHP block's siamesed cylinders have a 0.230-inch minimum wall thickness at 4.165-inch bore diameter. Other features include a true priority-main oiling system that ensures reliable lubrication at high rpm, ductile iron main bearing caps (with splayed four-bolt caps on the center mains), 0.625-inch thick decks with blind head bolt holes, and clearance for long-stroke crankshafts.
The SHP block retains the first-generation small-block's original dimensions and is compatible with stock components, including OEM-style hydraulic roller lifters and camshafts, steel and plastic timing chain covers, side and front motor mounts, clutch linkage pivots, and mechanical fuel pumps.
As a complement to the SHP block, Dart has developed pre-engineered, dyno-tested combinations that make it easy to build a powerful and durable performance engine at a very affordable price. So, you can buy just the bare block or an SHP-assembled short-block that includes a crankshaft, connecting rods, pistons, and rings. Dart also offers top-end kits which include cylinder head assemblies, an intake manifold, valve covers, fasteners, gaskets, and spark plugs.
SHP short-block assemblies are available in 372ci (4.125-inch bore x 3.48-inch stroke) and 400ci (4.125 x 3.75) combinations. Both versions feature premium quality components, including an internally balanced steel crankshaft, forged 4340 steel I-beam connecting rods with 3/8-inch cap screws, hypereutectic flat-top pistons with full floating wristpins, Hastings moly rings, Clevite bearings, and coated cam bearings. Top-end kits include Dart Iron Eagle or PRO1 aluminum cylinder head assemblies with stainless steel valves and dual-valve springs, a Dart aluminum intake manifold, chrome-plated Dart valve covers, fasteners, gaskets, and spark plugs.
Both SHP engine combinations make big horsepower on a budget. A prototype 400ci engine with 10.5:1 compression, a hydraulic roller cam, Dart 200cc cylinder heads, and a Dart single-plane intake manifold made 525 hp at 6,000 rpm and 525 lb-ft torque at 4000 rpm. A 372ci SHP engine assembly with 9.5:1 compression ratio and 180cc heads with a Dart dual-plane intake manifold produced 470 hp at 5,800 rpm and 470 lb-ft torque at 4,200 rpm. These motors are the perfect engine for oval track racers needing to make 500 to 600 hp on a budget.