2. Like the 4.8L, the 5.3L had logged over 150,000 miles, but was still running strong. Equipped as the 4.8L, the larger 5.3L produced 344 hp at 5,100 rpm and 379 lb-ft at 4,300 rpm. The 5.3L offered only slightly more peak power but a significant increase in torque. Using the same heads, cam and intake, the 5.3L produced peak power and torque at a lower rpm than the smaller 4.8L.