Its not quite that simple. Horsepower is horsepower. As long as the same number of shifts are made, two cars of the same weight with the same horsepower output should be nearly identical down the track so long as one of them doesn't have an overly-peaky torque curve [which the Viper doesn't]
The final drive ratio will make up the difference. A car with a lower redline and more torque will simply be geared lower than the car with the higher redline- as it must be making less torque at a higher RPM to have the same horsepower output. You see? It doesn't really matter.
Now, if you just raise the redline, and can continue to make power- of course, the car will get faster, but you are also making considerably more horsepower by default. Its just not an apples to apples comparison.
IMO, the Viper's main problem is that due to its lower redline, it must make considerably more torque than some of its higher RPM counterparts to create the same power output. Now, this does help in one way as we dont have the lag issues, out of peak torque issues, etc as the high revving high power cars often have, but, we do have a severe problem with keeping transmissions together as a result. It is far easier to make something with the small diameter of a gear to spin a few thousand RPM higher... however, making them handle 500 extra lb's of torque instead is a whole other story.
As the market has told, when you get a viper to hook, and put a trans in it that can handle the torque... it is a brutal combination.
