The old saying, "There's no replacement for displacement," is dead-on accurate. Sure, you can stuff a big, nasty camshaft into a smaller engine, or spin that same engine into the rpm stratosphere and make more power, but extra cubes yields something that real performance junkies find more beneficial: torque. When it comes to going fast, torque is king and it's one reason why old-school big-block Chevy engines still command respect. Of course, the down side to all that big-block goodness is weight. It's a give-and-take deal; at least it used to be. Today it's possible to get crazy displacement even in the diminutive small-block package. For example, GM's line of lightweight aluminum LS engines started out at around 350 cubic inches. As time passed, that displacement steadily grew to 364, 376, and eventually topped out at 427 glorious inches in the LS7. But the power-mad masses clamored for more. The problem was that the iron-sleeved aluminum blocks could only be punched out so far before getting dangerously thin in the cylinder wall department. Of course there was the stroke side of the displacement calculation, but the factory sleeves were only so long. The solution turned out to be ditching the GM sleeves and going aftermarket.
Now, this isn't something you're going to be able to do yourself using common hand tools in your garage. It involves very specialized and expensive equipment, but more importantly it requires someone with the skill and experience to pull off the surgery. That's where Steve Demirjian, of Race Engine Development, comes in. He's been in the racing engine business since 1972, and that equates to a lot of knowledge of what works and what doesn't. In regards to sleeves, he's been working with Darton for quite some time and is even one of the patent holders for their Modular Integrated Deck (MID) sleeve system. In other words, he was the perfect guy to help us up the displacement of our LS engine. The MID system was developed by Darton to address the factory blocks design weakness of cylinder stability due to the poor support at the upper deck area. GM's "cast in sleeves" makes the factory engines affordable, and they are great to a certain power level, but lacking when it comes to high power, boosted, or, as in our case, larger bore sizes. When the Darton sleeves are siamesed and nested they create a solid deck of sleeve flanges held in tension. This reinforces the upper deck area and provides for individual replacement with what Darton calls Modular Integrated Deck (MID). Also, this design enhances water flow from block to head and promotes stability of cooling since all the sleeves are of the "wet" design. Unlike factory sleeves, water flows all the way around the cylinders, which promotes cooling and helps control detonation. You can find more tasty tidbits about Darton's MID sleeves by hitting up their website.