GM’s most recent offering in the LT Gen V iron block lineup is what horsepower dreams are made of. Known as the L8T, you can find the motor in the 2020 and newer Chevrolet and GMC HD trucks. The newly designed block is thick in all the right places coming in at 6.6-liters, which lends itself to being the perfect factory platform to build on. The team at Scoggin-Dickey Parts Center (SDPC) Raceshop saw this potential and wanted to see what they could do if they put their touches on an L8T build, with the goal being 2,000 horsepower safely.
Inside Scoggin-Dickey’s L8T
The SDPC Raceshop crew began the project by sourcing a new L8T block and crank. To prepare their new block for the power numbers they had in mind, the team installed billet steel main caps and a set of ARP studs. In addition, as part of their Race Prep package, the block is drilled to accept both LT and LS style cylinder heads. For this build, SDPC bolted on a set of their CNC ported LT4 heads that utilize the factory rocker arms. They also added their CHE Trunnion upgrade along with upgraded valve springs and pushrods. Internally, a set of Callies Ultra rods and Wiseco forged pistons with Total Seal piston rings round out the rotating assembly. The factory crankshaft is a forged piece, more than capable of handling the power level the team was attempting to achieve.
While Scoggin-Dickey was pretty open with this build, they didn’t disclose the specs of the camshaft, although it does allow the engine to spin to a 7,500 rpm redline easily. A Holley Hi-Ram intake manifold coupled with Holley’s 102 mm throttle body was pulled from the SDPC shelves and put into action for the top end of this build. To finish off the core of this beast, the Raceshop used more parts from the SDPC catalog. A balancer from ATI Performance Products, Moroso oil pan, Peterson Fluid Systems external oil pump, and Hooker Blackheart exhaust manifolds complete the engine.
For making the level of power the SDPC guys wanted, they decided to go with twin turbochargers. In this case, two of Precision’s 7685 ball-bearing turbos push 32-pounds of boost through a Shearer Fabrication water-to-air intercooler. Precision 46 mm wastegates and 64 mm blow-off valves keep the boost under control. The fuel of choice is VP C16 delivered by port injection using Holley EFI fuel rails and injectors.
The Raceshop used Holley’s Dominator EFI system for electronics to perform the testing. Strapped to the engine dyno and ready to make some noise, the SDPC L8T put up power numbers sure to raise the eyebrows of any enthusiast. Surpassing the goal of 2,000 horsepower, the L8T made 2,077 ponies and 1,785 lb-ft of torque at 6,500 rpm. Big numbers for a stock block and crank using primarily off-the-shelf parts. This means the same monster can be in your next project simply by ordering the parts from Scoggin-Dickey Parts Center. The guys at SDPC want you to build an L8T of your own so badly that they provided a build list with details and part numbers.
SDPC Raceshop L8T Build
SDPC Raceshop modified L8T Block PN: SDR98759
Chevrolet Performance GEN-V L8T Crankshaft PN: 12708884
Holley Hi-Ram w/ PFI provisions PN: 300-140
Johnson Hydraulic Lifters PN: 2126LSR
Callies Performance Products Ultra Rods PN: U17175
Wiseco Automotive 2618 Forged Aluminum Pistons
Total Seal Piston Rings
ATI Performance Products Balancer
Moroso Performance Products, Inc. Oil Pan PN: 21154
Peterson Fluid Systems External Oil Pump
SDPC Raceshop CNC Ported LT4 Cylinder Heads PN: SDR78973
GM Production 1.8:1 Rocker Arms w/CHE Precision Inc. Trunnions
CHE Trunnion Upgrade PN: CHE4290
Holley 102mm Throttle Body
Shearer Fabrications Intercooler
Precision Turbo & Engine 7685 turbos, 46 mm wastegates, 64 mm BOVs
Hooker Blackheart Exhaust Manifolds
Maxima Racing Oils 15W-50 Break-in Oil