One of the great features of the LS engine is that it makes strong power in a compact package. That’s why it’s so popular for swaps – it has all the benefits of a modern engine, but it easily fits into vehicles that are a squeeze for Gen III Hemi or contemporary Ford V8s. And when built right, the LS can make great power without bulky forced-induction systems, further simplifying swaps.

The foundation for this build is a 6.0-liter iron block that originally came from either a GM LQ4 or LQ9 (the only real difference is that the LQ4 has compression-lowering dished pistons). These engines can be found in pickups and large SUVs at junkyards across the country.

The displacement will be bumped up 42 cubic inches, to 408. To get that we’re using a forged stroker crank from Liberty Performance Components with 4.00-inches of swing. It’s the newer style with a 58-tooth reluctor wheel to provide more accurate crank position data for the Holley Terminator X ECU we’ll be using to control everything. If you haven’t heard of Liberty Performance Components, that’s likely because the brand sells almost exclusively to engine builders, but they’re great on the performance/cost ratio.

The forged H-beam connecting rods are also from Liberty Performance; they’re 6.125-inches long from center to center, and they’re topped with a set of 4.030 diameter forged pistons from DSS.

The camshaft is a hydraulic roller from Comp Cams. It’s ground with 235/243 degrees of duration for both the intake and exhaust at 0.050-inches of tappet lift. There’s 110-degrees of lobe separation on a 105-degree centerline. Lobe lift is 0.365 inches for the intake and 0.367 for the exhaust.

One way we’re making power is with a relatively high compression ratio. The pistons will be a few thousandths of an inch above the deck of the block because we’re using stock head gaskets with a 0.051-inch compressed thickness. Final compression ratio will be 10.9:1, which can easily be handled by the Holley Terminator X engine management system.

The roller lifters are slightly upgraded over stock, but still utilize the stock-style lifter trays, which saves the added expense of tie-bar lifters. A neat trick that lead engine builder Larry Broeker uses is to pop the lifters in the trays first and then install the entire assembly into the block at once. This saves a lot of hassle trying to get the trays aligned over four individual lifters once they are already in their lifter bores.

The cylinder heads are Prestige Motorsports’ own casting. They’re as-cast in both the ports and combustion chambers, but the casting quality is excellent. To maximize power, they’re a hybrid head; they have the better LS7-style ports, but they still accept stock-style LS3 intake manifolds and exhaust. The intake runners are 255cc and the chambers are 69cc.

Up top, the rockers are the stock 1.7:1 ratio but have an upgraded trunnion for better longevity. The valve springs have approximately 140 pounds on the seat and 400 fully open (which is 0.621” for the intakes and 0.624” for the exhausts).

The block is the older generation design that placed the cam position sensor at the back. We’ll be moving it to the front of the engine, on the timing cover like newer-style LS engines. The valley cover is a Holley trussed billet aluminum unit made for LS1-style blocks, and a billet aluminum plug will fill the hole for the cam position sensor. The hardline steam kit is from Earl’s with stainless-steel hard lines that won’t rust or corrode.

The cast aluminum valve covers are from Holley, and we like that the black powder coat is super durable and doesn’t scratch easily. These have held up very well in other builds.

Providing power to the spark plugs are eight MSD Pro Power coils. Compared to stock LS units, these send much more energy to the plugs for a better burn. Routing that power to the plugs is a set of beefy 8.0 mm Holley LS plug wires.

The intake manifold is a Holley Ultra Lo-Ram, powder coated in black. The Ultra Lo-Ram minimizes the height of both the top of the intake manifold and the throttle body, to give you the best chance of fitting everything under the low-slung hood of either a sports or muscle car. The Ultra Lo-Ram does great in both naturally aspirated and boosted applications, which is why we included this shot. Notice how Holley engineers sculpted the runner entrances inside the plenum to enhance flow and increase the effective runner length a significant amount.

Here’s a look at the complete intake. The Ultra Lo-Ram is modular, with options to customize it to your needs. For example, if you’re running boost, you can swap out the plenum top for one with an easily accessible burst panel. Everything is sealed with O-rings, so installation is a piece of cake.

The throttle body is a large-bore billet aluminum Holley 105 mm unit that can move tons of air. Swapping an engine with drive-by-wire throttle into an older vehicle can introduce headaches. A physical cable connecting the throttle pedal to the throttle body makes life easier when dropping an LS into any number of older cars.

The billet fuel rails come with the intake manifold kit and arrive with two sets of mounts to adjust the height for the most common injectors used in LS builds. Ours are a set of 42 pound-per-hour injectors from Holley.

All the engine accessories will be driven with Holley’s mid-mount system. The genius of this design is that everything mounts off the custom water pump casting. That keeps the accessories tight and compact to the engine to eliminate chassis interference issues.

The guys at Prestige Motorsports put the Giveaway LS onto the dyno to find out what this engine is capable of. Handling all the engine controls is the Holley Terminator X ECU, mounted just behind and to the left of the engine for dyno runs.

On the dyno we saw peaks of 518.1 lb/ft of torque at 4,900 rpm and 580.8 horsepower at 6,400 – excellent results for a naturally aspirated engine burning pump gas. Even though the peak was at the end of the pull, the power had started to level out – we probably wouldn’t have seen much more than this if we had extended the run.