They say variety is the spice of life, and that certainly holds true for Chevy truck owners. As difficult as it is to believe, the vast majority of trucks purchased remain bone stock. Modifications to these stockers tend to be more of the tree-shaped, air freshener variety than some performance enhancement underhood. Many owners don't even know where to find the hood latch, let alone what to modify once they successfully locate the engine bay. Truckin readers tend to populate the other end of the performance spectrum, a position unencumbered by pine-scented floral fixtures. Despite sharing a desire for performance, variety is still the order of the day. For some, it's a simple cam swap combined with an air intake and cat-back exhaust, while others go whole hog and opt for a maximum-effort, all-motor stroker. Recognizing (and applauding) this diversity, we decided to offer up a little variety of our own—Truckin style. When all was said and done, we tested no less than five different 5.3L combinations, including the stock motor, ranging from mild to wild. Check them out and decide which one is right for your Chevy truck.
Test Motor #1-Stock LM7 5.3-Liter
TB: Accufab 78 mm
Headers: QTP 1¾-inch long-tube
Peak Power: 363 hp at 5,300 rpm
Peak Torque: 385 lb-ft at 4,400 rpm
Torque Curve: Exceeded 360 lb-ft of torque from 3,700-5,200 rpm
Before running any of the modified combinations on the engine dyno, we needed power numbers on a stock motor. The 160.000-mile 5.3-liter was installed on the engine dyno and run with a FAST XFI/XIM management system. The LM7 was run with a set of QTP headers, a manual Accufab throttle body (our wrecking yard motor was not supplied with a stock throttle body) and a Meziere electric water pump. In otherwise stock trim, the 5.3-liter produced 356 hp at 5,400 rpm and 378 lb-ft of torque at 4,300 rpm. Tuned for towing, torque production exceeded 360 lb-ft from 3,700 rpm to 5,100 rpm. Even down at 2,500 rpm, the little 5.3-liter pumped out 345 lb-ft. Is it any wonder the affordable and powerful 5.3-liter is fast becoming the swap engine of choice?