Competition Products’ SHP LS Next-Based Short Block Packs A Punch


If you’re in the market for a capable LS short-block, you’ve got a lot of options to choose from these days. It seems like every vendor out there has at least several variations of strokers to choose from; all of which are stuffed with high-strength components and ready to take as much horsepower and abuse as you are willing to dish out. But when it comes to bang-for-the-buck, there are few manufacturers that can outdo Competition Products.

Competition Products has been building engines for a long time, and if you’ve ever wandered through their pages, you would see that they have a seemingly never ending amount of options to choose from. From big-blocks to traditional small-blocks and of course LS. What ever you want, they’ve either got it or can build it. That’s one of the reasons we were so stoked when we heard about their new short-block based on Dart’s SHP LS Next block.


Building Blocks

Any great engine starts with a solid foundation, a truism that Competition Products is well aware of. That’s why they started with the SHP LS Next block. Competition Products has been offering short-blocks based on the standard LS Next block for sometime, but when the SHP variant was released, they saw an opportunity to provide customers with a perhaps more compatible foundation for those that wanted to use the mill on the street.

“The reason we decided to build this is we had people that didn’t want to bother with the different oil pan rails that you have to use with the LS Next block that our previous short-blocks used,” said Brian Adix of Competition Products. “The LS Next also has a few things that don’t line up with factory parts, but the SHP block we used for this one, all of that lines up.”


And while the SHP block has plenty of provisions for factory equipment, it sacrificed nothing in the way of capabilities to bring them to the table. The SHP block offers six bolt per cylinder provisions, siamesed cylinders with thick walls capable of handling large bore diameters, cylinder barrels that extend .375 of an inch at the bottom of the bores, scalloped water jackets, splayed outer bolts on the middle main bearing caps, and it’s capable of taking up to a 4.125-inch stroke.

The SHP is also a fully skirted iron block which, as we previously mentioned before, eliminates the need to use custom oil pans or rails. This allows you to use any oiling system that you may have already invested in with the new block. It also comes with all of the OE bolt holes for the starter, water pump and accessories which makes it much easier to use than the LS Next block in a vehicle destined for street/strip duties.

The Long And Short Of It

By now you are probably wondering just what types of configurations Competition Product’s short-blocks come in. With a max bore size of 4.185 inches and max stroke of 4.125 inches, Competition is capable of building you an engine all the way up to 454 cubic inches—if you want a custom build—however, they off their short-blocks in two popular sizes.

The block is bored to the appropriate specifications and then checked for roundness to ensure the cylinders are within spec.

“It comes in two different sizes, a 403, which has a 4.005-inch bore and a 427 which is a 4.125-inch bore, and both use a 4-inch stroke,” Adix said. “We offer them in those two sizes because they are popular with a large majority of our customers–we can do any combination a customer would like, but it is typically slightly more expensive to go that route.”

It’s What’s On The Inside That Counts

For the slugs, Competition Products turned to Howard’s Racing Products for a set of their ProMax pistons, which Adix tells us are revolutionary in both construction and cost. In the past, Howards Racing Products has focused mainly on the big- and small-block Chevrolet markets but recently moved into producing LS-specific components after seeing how large the demand was for the platform.

“Howard’s Racing Products didn’t originally have any pistons for the LS engines before this, but they’ve always done really, really well on the big-block and small-block Chevrolets, so they brought some of that ingenuity and know-how to their LS pistons,” Adix said. “One of the things they did was go with a 2618 forging that was very strong and got it to where it is a great piston but kept the price down on them.”

Here you can see the Howards Plasma Moly True Seal being installed on the ProMax pistons. They are then mated with the Callies forged connecting rods.

Cheap isn’t usually associated with strong, but in Competition Product’s case that is exactly what you’ll get. They have gone above and beyond to make sure that their short-blocks are equipped with a capable piston, that still allows them to keep costs down, while providing the customer with high quality components.

“In a lot of competitors’ pistons, they will typically use a lesser material like 4032 to try to keep the costs down—which, don’t get me wrong, is still a great material but it means they have a higher silicon content which compromises their strength,” Adix said. “Not only do the ProMax pistons use a stronger material for their construction, they also use a proprietary X-shaped casting process that allows them to use less material but retain the strength of the piston—it’s better structure with less weight.”

The pistons are completely CNC’d and feature larger valve pockets than normal to prevent piston-to-valve incurrences. They are available in dish sizes up to -12 cc which brings the static compression ratio to somewhere between 10.0:1 to 11.0:1—if run in conjunction with 66 cc heads—and are paired with a set of 1.5, 1.5, 3.0 mm Howard’s True Seal rings. The wrist pins are also lightweight and aircraft quality to match the pistons.

This piston rings are oiled before inserting them in the block.

For the crankshaft, Competition Products turned to Callies for one of their Comp Star 4340 forged units which provides the mill with plenty of strength. For the connecting rods, Callies Comp Stars were once again utilized in a standard 6.125-inch length.

On the bearings, Competition utilized a Clevite H-series bearing to keep everything turning smoothly on the bottom-end, and Dart coated cam bearings keeps everything spinning upstairs. The entire assembly is also blue printed and balanced during assembly.

Competition also takes the intended application into account as well. For example, say a customer was planning to run boost or nitrous; the ring gap would then be adjusted accordingly to ensure the mill would operate trouble free under even the most severe conditions.

All assembly of the short-blocks are handled at Dart by their trained engine technicians—who just so happened to also build Pro Stock engines—and can be built to custom specs if the customer so chooses.


Once installed, the pistons are checked for deck height, ensuring that they are within standard specifications.


With all of the quality components that go into building these awesome short-blocks, you’d be right to think that they are far outside the realm of affordability, but that’s where you’d be wrong. Competition Products goes to great lengths to not only assure that you are getting the highest quality product possible, but that it is as cost effective as possible as well.

“We are trying to break into the LS market and that’s why we are pushing so hard to be so competitive on price,” Adix said. “This one is a hair cheaper than the standard LS Next short-block. Just to give you a hint, the new one, the SHP, is going to sell for $5,679.95. That’s either the 403 or the 427—they both cost the same to build them, some people just like smaller bore because of the heads they are looking to use with them.”

Here you can see how the barrel extends further than stock and keeps the piston from excessively rocking with such an aggressive stroke. The Callies forged crankshaft is then torqued into place.

Just to sum up, that’s $5,679.95 for an all-forged short-block LS that utilizes cutting edge components assembled by a former team of Pro Stock engine builders. This mill can take almost anything you can dish out and keep coming. As we mentioned earlier, custom builds starting with these specifications are also possible if you’re willing to dish out a few more Benjamins.

The 441 cubic inch standard LS Next, on the other hand, starts at $5,997.95, making the SHP-based build about $300 cheaper. However, when you take into consideration the fact that if you use the standard LS Next block, you’re going to spend even more money on components to make it fit, it makes the SHP block a lot more cost effective by comparison. 


Summing It All Up

As we mentioned earlier, there is no shortage of well-built LS short-blocks out there from many trusted vendors, but when it comes to getting the highest quality components and build quality possible for the least amount of coin, you’ll find it hard to beat Competition Products.

So, if you’re on the hunt for a bullet proof LS short-block, and you don’t want to have to take a second mortgage out on your house to bring one home, you might want to give Competition Products a call for one of their SHP LS Next-based short-blocks.

Article Sources

About the author

Chase Christensen

Chase Christensen hails from Salt Lake City, and grew up around high-performance GM vehicles. He took possession of his very first F-body— an ’86 Trans Am— at the age of 13 and has been wrenching ever since.
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