Spec Sheet 400hp LS2
Take one 400hp LS2 and install it on the dyno and you have an easy 400 horsepower. For this test we equipped the LS2 with Hooker headers and an open exhaust. With optimized air/fuel and timing curves, the LS2 pumped out 462 hp and 461 lb-ft.
| Block | Stock 2003 LS2 |
| Crank | Stock 2003 LS2 (Stock Stroke) |
| Rods | Stock 2003 LS2 |
| Pistons | Stock 2003 LS2 |
| Compression | 10.9:1 |
| Cylinder Heads | Stock 2003 LS2 |
| Cam | Stock 2003 LS2 |
| Intake Manifold | Stock 2003 LS2 |
| Throttle Body | Stock 2003 LS2 |
| Injectors | 36 LB. |
| Management System | FAST |
| Headers | Hooker 1 5/8 |
| Exhaust | 18-IN. Collector Extension |
| Fuel | (91-Octane Rocket-Brand Race Gas) |
If you think extracting 400 horsepower from an LS1 was easy, things get downright simple with the larger LS2. Given its factory rating of 400 hp, it's not surprising that the LS2 produced 462 hp and 461 lb-ft of torque with just a set of Hooker headers. Compared to the smaller LS1, the LS2 offered not only more peak power, but also more power throughout the rev range. Down at 3,100 rpm, the LS2 produced nearly 60 more lb-ft of torque.
Spec Sheet 500hp LS1
Total Engine Airflow supplied a set of ported 5.3L truck heads. When combined with a small Comp cam and FAST LSX intake, the result was 535 hp and 478 lb-ft of torque.
| Block | Stock 1998 LS1 |
| Crank | Stock 1998 LS1 (Stock Stroke) |
| Rods | Stock 1998 LS1 |
| Pistons | Stock 1998 LS1 |
| Compression | 10.2:1 |
| Cylinder Heads | CNC-Ported 5.3L Truck (Total Engine Airflow) |
| Cam | COMP XR265HR |
| Lift | .522/.529 |
| Duration | 212 In., 218 Ex. |
| Intake Manifold | FAST LSX |
| Throttle Body | FAST |
| Injectors | 36 lb. |
| Management System | FAST |
| Headers | Hooker 1 5/8 |
| Exhaust | 18-in. Collector Extension |
| Fuel | (91-Octane Rocket-Brand Race Gas) |
As impressive as the Gen 3 motors are in stock trim, they're even more so once modified. Using the same LS1 crate motor as a starting point, eclipsing the 500hp mark required only a set of aftermarket heads, a mild cam, and an intake manifold, though the LS6 intake would also work well at this power level. The LS1 was treated to a set of ported 5.3L truck heads from Total Engine Airflow, a Comp XR265HR cam, and a FAST LSX intake. The smaller combustion chambers (61cc) on the 5.3L heads increased the compression ratio by .5 point. When combined with the mild cam and LSX intake, the result was 535 hp and 478 lb-ft of torque. Note that the power curve was still climbing at our shutoff point of 6,200 rpm.