well from owning both a 1994 5.7 reg cab 5 speed and a 2007 classic 5.3(swapped) 5-speed. the power band in the 5.3 is wider than the 5.7. both engines in stock trim pulling the same weight( gsxr600 in the bed, 2 gsxr 1000;s on the trailer); i kinda struggled in the 5.7 to get up to 100mph in 4th/ cruise in 5th @100 with the 5.3. plus the efficent 5.3 is roughly 5-7mpg better pulling the weight mentioned above.