This Modified 821HP Chevy Performance LT4 Crate Engine Sold For More Than A New SUV

Although the average transaction price for a new car recently broke the $50,000 barrier, $40,250 can still get you a fair amount of vehicle. For example, that kind of budget could just about get out the door in a 2025 Toyota RAV4 Hybrid Woodland Edition — even with the Weather Pack's heated leather steering wheel and seats. That configuration is currently priced at $38,445, which includes a $36,070 suggested price, $925 for the option package, and $1,450 in destination fees. (Pricing for the 2026 RAV4, which adds a PHEV GR Sport Version, has yet to be announced.)

Alternatively, you could have spent the cost of that RAV4, and more, on a single engine. And it's no ordinary motor. We're talking about a supercharged 6.2-liter LT4 V8 that originally came as a crate engine from Chevrolet Performance. The mill already packed serious punch fresh from the factory, showcasing up to 650 horsepower and 650 pound-feet of torque, but that was just a starting point for Aaron Kurt and the team at Late Model Engines. After they worked their magic on this incredible motor — finishing the job in November of 2024 — output was dialed up to 821 horses and 797 lb-ft. 

To be clear, that's as tested on a dynamometer. The engine still had not yet been installed in a vehicle at the time it was recently sold on Bring a Trailer— for that tidy sum of $40,250.

The stock LT4 made a strong foundation for the build, although Late Model Engines did precision-bore the cylinders to 4.07 inches — up slightly from the original 4.065 inches — to house the Diamond 2K forged pistons. Those, in turn, have been updated with Total Seal piston rings and I-beam connecting rods from Texas Speed, and what they connect to is a forged crankshaft from Callies. Other high-performance hardware in the mix includes a Cam Motion camshaft plus a Holley accessory drive.

The crew did more than just bolt on other people's products. Details like the billet timing chain, timing cover, and titanium valve retainers all come from Late Model Engines, and team members were responsible for porting both the cylinder heads and supercharger. Remember, that's when you polish and smooth an engine's exhaust and intake ports for easier airflow. There are pros and cons to porting your cylinder heads, of course.

What's particularly interesting, however, is that Late Model Engines seems to have dumped the LT4's standard direct-injection system at the same time as it was porting the heads. The reasoning behind this isn't mentioned, but some self-proclaimed performance experts seem to believe port injection produces more power than direct injection. That seems to have been pretty well disproved a few years ago, but perhaps the company hadn't received the message when it made this build.

A few years before building that supercharged LT4 crate engine, Late Model Engines developed a new motor for Accelerated Racing Solutions, a California shop that wanted to install it in a Chevrolet Camaro. The top priority was pure power, although there was a catch: the company couldn't use forced induction. With that in mind, it turned to one of General Motors' LT1 V8s as the rock-solid base motor for its effort. Which, notably, included raising the compression ratio from the engine's standard 11.5:1 to 14:1. That increase is good for performance because when an engine operates at a higher compression ratio, it burns fuel more efficiently to produce more power.

Late Model Engines increased the engine's maximum speed as well. While the standard LT1 is meant to max out at 6,600 rpm, the upgraded unit could spin at 8,500. Sure, the uprated compression ratio and raised redline put extra stress on the mill, but — as reported by EngineLabs — "This engine is so well engineered that the crew at LME knew that they could go to 14:1 compression and spin to 8,500 rpm without fear." As a result, the custom LT1 could pour out 822 horsepower and 635 lb-ft.

Does your current ride need that kind of heart transplant? GM has a long list of crate engines available, and we can help you sort through some of the popular ones by looking at what sets GM's LS and LT engines apart.