I think it would depend on what you have done to the motor. I have a friend that has one on a pretty bad Cutlass and it doesn't do to good of a job on the street. He uses the car mainly for drag racing but shows it from time to time and it's always hot from normal driving.
Had one on my 93 for 2 years. Runs quiet, car runs way cooler and i make noticeable improvement from 4000 rpm upwards. Should dyno about 11 rwhp on an LT1, probably 13 rwhp on an LT4 (because of the higher redline).:cheers: