man the iroc isn't a muscle car, it was a shot at bringing them back. if you look up the stats, old muscle big block cars had from 375-475 hp and torque that in stock form would throw four thousand pound car off the ground and twist the frame on the drag strip. There is one particular car that comes to mind with that. But I can't remeber whether it was a chevy or a mopar.
This is a muscle car:
The Z and the S sports cars. My Iroc is a 2 door sedan with the capabilty to lay a 200ft burnout without the drop of the clutch. The only thing that can still be called a muscle car is the vette. 550hp, 475tq. all from a 427cid smallblock. And the reason why it can even be considered to be a muscle car is that it was around during that time and it was a muscle/pony car.
As far as fairly low revving i have taken mine up to 7K in a race, idoitic but it has been done. Oh and as far as real muscle cars, they would generally redline around 6-6500rpm. Before the days of emissions and smogger motors. Cause you see if i remove and my emissions equipment or even replace them with new stuff(and fuel injectors) i would be sitting around 300hp. Just its still a smogger motor.