ENGINE's Sound

Hi everyone.
I recently bought 1991 Eagle 2000 GTX AWD ,2.0 DOHC.5 spd stand.
When i drive on the highway at 100 km/h or more the engine works really,really!!! loud at approx 3500-4000 RPM
don't know if it's allright for that car on not
Please help.Any suggestions would be appreciated.Thanks!!!

sorry but could you be a tad more specific? what kind of noise?? what mods so you have or is there if any at all?

The noise i am talking about is if you would run your car at all 9000 RPM