PART EIGHT: LIGHTING THE FIRE
We went over the cooler points of the MSD 6LS ignition box and coils during the dyno test. Since the box was plugged into the cam, crankshaft, and MAP sensors already, once the engine was in the truck we simply had to wire up the ground wire to the block and a 12-volt positive ignition wire to the steering column switch. The engine lit right off with a twist of the key.
The Final Word
After a short chassis dyno-tuning session at Westech Performance to obtain the most fuel-efficient tune-up that still made good power, I hit the road. It was interesting to see that the engine lost about 80 horsepower on the chassis dyno due to the parasitic losses from spinning the drivetrain. Still, the engine put over 308 hp to the rear wheels.
The Parts Racer will barbecue the passenger-side rear wheel with ease, even with 3.08 cogs in the open 12-bolt differential. Out on the highway, those cogs, lockup torque converter, and the 27.5-inch-tall tires yield a super-low 1,600-rpm cruising rpm at 70 mph. At 80 mph, the engine is barely spinning 1,900 rpm, and the engine is not lugging thanks to the 300-plus lb-ft of torque the LS327 is making at that rpm and the perfect match of the transmission, converter, and camshaft. It reminds me of a few late-model Corvettes that I've driven that could effortlessly cruise at such a low rpm but still push you back into the seat when you hammered down the gas pedal, and get great mileage. Check back next month for a stellar road trip story and see how well we fared at the gas pump. We plan on putting 4,500 miles on this beast in nine days, so there will be plenty of opportunities to stress-test this combo.