I don't really think that the 5.7 was underpowered, I think that Chevy V8's just get tired really easily...
Nothing is really under powered, even that 120hp 300-6, if you keep your expectations in line. The 5.8 makes the same exact power as the 5.7, and feels exactly the same driving it. They both have enough power, you just have to spin them to get it. 200hp is enough to tow about anything, if you have a gear that lets you use it at the speed you want to go. You can keep up in traffic with 6-7,000# on the hitch if you are willing to hold the engine at 4,000 rpm going up hills. Adding a hundred cubes is the trick to keeping the revs managable.I don't really think that the 5.7 was underpowered, I think that Chevy V8's just get tired really easily...