These blocks get fully machined for Darton sleeves at our facility using seasoned GM Gen 4 aluminum blocks on our Rottler CNC machine. These sleeves have steps in them to alleviate the possibility of …

Flag Motorsports offers in house LS and LT block sleeving, alongside optional machine work processes. Our sleeved blocks allow for bore sizes between 3.780 and 4.185. Each bore is honed specifically to …

Cylinder Wall Thickness: Sleeve OD on all LS blocks are 4.280”+ approximately .200” aluminum surrounding it (except between the cylinders of course). These blocks can safely be bored to 4.165” …

Engineers at RHS® have designed a high performance aluminum engine block for GM LS applications to meet the needs of race and street performance engine builders alike.

Dec 29, 2024 · Block Applications: The BMP aluminum blocks are designed to be a high Performance replacement for the GM LS series blocks. Deck Thickness: .750 minimum. Cam Bearings: Durabond …

Perfect for racing, street, or custom applications, our LS Next aluminum blocks deliver exceptional power and strength while being 60 lbs. lighter than factory iron blocks and retaining provisions for …

Dec 25, 2025 · Engineered with deep side skirts, 6-bolt cross-bolted main caps, and the GM lightweight aluminum casting - this block gives you the assurance you need for building a new engine with a …

The LS7 block is well known for having brittle sleeves that crack under higher horsepower, which usually cracks the aluminum behind the sleeve as well. Resleeving the block before there is an issue is a …

Thompson Motorsports GM LS Sleeved All Forged 388ci - 440ci - 1000/1200hp $8,928.85 USD