Part Two: Dyno Tuning Cont'd
7a. This micro switch is provided by UMI and is bolted to the base of the carburetor to contact the throttle linkage at idle. | 
7b. When the carburetor is throttled down to the idle position, the micro switch is triggered and sends a signal to the computer. The computer recognizes the engine is idling and then conditions the ignition timing to smooth out the engine's idle. If the engine has an aggressive camshaft that makes the idle rough, the computer will constantly adjust the timing advance to match the idle and smooth it out. If the engine rpm surges upward, the computer removes timing, and if the engine rpm slows down, the computer adds in more timing until the engine is running smoothly. It's pretty trick and makes navigating parking lots with a rumpity-rump camshaft easier. | 
8a. This manifold absolute pressure sensor is also employed to further aid the computer in tuning. |
8b. | 
9. The last connection we made to the motor was a line to monitor the oil pressure via this adapter above the oil filter location. | 
10. We tested our LS2 using a pair of Hooker headers that featured 2-1/8-inch primary tubes and 3-1/2-inch collectors. |
The Final Word
This is a killer engine for any project truck. Our dyno-tuning session found that GMPP has once again underrated its crate motor, because this thing produced 480 hp at 6,000 rpm. Peak torque occurs at 4,900 rpm with 453 lb-ft of torque measured at the flywheel. The really exciting number happens at just 2,500 rpm, though; the LS2 makes a whopping 400 lb-ft of torque, right down where we'd be cruising at. If you are considering swapping a cast-iron big-block into your ride, you might want to also know that this small-block weighs approximately 200 pounds less, which translates into fewer pounds out of the nose of the truck and a better front and rear bias. This means better handling, with power rivaling most big-blocks.
Since our dyno test, we have installed this LS2 into our '67 Chevy C10 project and are happy to report that the motor only needed five wires connected to make it run in our truck after leaving the dyno. We'll report back on how the truck drives and what else is needed to get the power to the rear wheels in an upcoming issue of ST.