Michael Accardi 
If you don’t love Chevrolet’s 7.0L small-block LS7 V8, why are you here? When the LS7 debuted in 2006 it was heavily based on the LS7.R featured under the hood of the Corvette C5.R as campaigned in the American Le Mans Series. The LS7’s 505 horses powered the C6 Corvette Z06 to incredible heights before the engine found its way into the 2014 Camaro Z/28.
Production of both the C6 Corvette Z06 and fifth-gen Camaro Z/28 ended several years ago, but General Motors continued to offer the LS7 through the Chevrolet Performance Catalog. This was then joined by the LS7-based LS427/570 crate engine; a wet-sumped small block V8 with an all-natural 570 horsepower. The LS427/570 only made its debut in June 2020 – just a year and a half ago, before Chevrolet yanked it off the shelf. In fact, Chevy Performance has been quietly killing off its LS-based crate engines while everybody ogles at high profile announcements like the 10.4L, 1,004 horsepower ZZ632 Big Block V8 that debuted at SEMA 2021.
Which brings us up to the present.
Reports started popping up on social media recently that many suppliers had begun marking the LS7 as discontinued on their sites. This was confirmed by checking the Chevrolet Performance website, where the beloved LS7 crate engine is shown as discontinued. Unfortunately, the 570 horsepower LS427/570 is based on the stock LS7 has been discontinued as well. But what if we were to tell you the LS7 isn’t totally dead?
Cruise through the latest version of the Chevrolet Performance Catalog available online and you’ll quickly find all the parts required to build the ultimate LS7 are all still available from GM. If you’re dedicated and willing to bear the cost you can build yourself an engine similar to the 7.0L LS7.R used in the C5.R. Part Number: 12480030 will net you the C5.R block which is manufactured from a unique aluminum alloy for greater strength, it has 4.117-inch finished bores, and includes billet steel main caps with premium 4340 fasteners and racing-quality head studs.
Yup, you can buy a Corvette Racing engine block.
The nice thing about the C5.R block is you can actually use other rectangle port LS-style heads provided they can accommodate at least 4.10-inch bores, although according to GM a 4.125-inch bore is preferred. Unfortunately, a C5.R block will run you almost double what a production LS7 block would cost.
If you’re looking for C5.R heads specifically, they’re available under P/N: 25534393. Keep in mind though, these heads were designed for professional porting so the final shape and size of the ports and combustion chamber will depend on whoever does the job. Additionally, there are no valve seats or guides, but the heads are capable of flowing enough air to produce over 800 horsepower naturally aspirated.
Another choice is the LSX-LS7 CNC-Ported Cylinder Head Assembly, available with P/N:19419197. These heads are fully CNC ported and come assembled with 2.200″ titanium intake and 1.610″ sodium-filled exhaust valves. In terms of cost, the C5.R heads only run a couple of hundred bucks more than a bare LS7 head.
As for the rotating assembly, between Chevrolet Performance and aftermarket suppliers, there are countless cranks, rods, and piston setups available in the appropriate sizes. While the Performance catalog still lists the stock LS7 crank and camshafts as available, hotter cams and stronger cranks made for LSX duty are easily found as well. Intake manifolds are available through GM in both carbureted and EFI formats, same goes for the aftermarket. Other parts like gaskets, seals, bolts, timing covers, sprockets, chains, sensors, etc. are all still available through the Performance Catalog.
No one said it would be easy to build yourself a C5.R engine clone but it will quickly become one of the only ways to get yourself anything resembling a GM factory-made 7.0L LS, even if there is some assembly required. Then again, there are plenty of aftermarket options available from brands like DART that would allow you to build something even better, but that’s another conversation entirely.
