Big horsepower gets expensive fast. Between the rotating assembly, cylinder heads, valvetrain and power adder, an LS build can burn through a budget before the first bolt gets tightened. Your engine needs a strong foundation—but buying one shouldn’t derail the entire project.

Enter the Smeding Performance Heavy-Duty 6-Bolt LS Iron Block. At $2,995, it brings an aggressive price to the aftermarket LS arena, backed by construction engineered for demanding performance applications. This is where the horsepower plan meets the checkbook—and both get something to smile about.

MORE BLOCK FOR YOUR MONEY

Smeding builds its heavy-duty foundation from 220 BHN Class 35 gray cast iron, pairing it with billet steel main caps, four-bolt splayed retention and 7/16-inch, 150,000-psi fasteners.

Those are meaningful specifications, not cosmetic upgrades. According to Smeding, the combination delivers the rigidity and bottom-end stability needed for increased cylinder pressure and RPM.

Spend wisely underneath, and there’s more room in the budget for everything going on top.

CLAMP DOWN ON CYLINDER PRESSURE

The six-bolt cylinder-head configuration adds clamping capability to help maintain head-gasket integrity. Smeding positions the block for high-output naturally aspirated and boosted combinations.

Whether your build sheet calls for a hard-hitting naturally aspirated engine or a boost-fed bruiser, the foundation deserves as much attention as the headline horsepower number.

OILING WITH A PURPOSE

Smeding’s priority-main three-galley oiling system provides a dedicated circuit for the crankshaft and connecting rods. The company says this improves oil distribution and supports demanding high-RPM operation.

It’s engineering you won’t see once the engine is assembled—but exactly the kind you want working behind the scenes.

BUILD IT YOUR WAY

Specifications include a 4.120-inch rough bore, 4.185-inch maximum bore and 9.240-inch deck height. A thrust plate and block-plug kit are included; 1/2-inch head-bolt machining and ARP main studs are optional upgrades. Confirm finish-machining and preparation requirements with Smeding or your engine builder. Product details.