I just had FRPP 4.10's installed the other day and WOW..what a difference it is! Only mods are Borla Stingers, MAC O/R Prochamber and JLT RAI. The RPM's jump so fast and the car takes off. It's not sluggish after 3rd gear either. Before, I would be in 4th gear for example, and if I punched it gain some speed, it would take a little bit to feel strong. Now its strong all the time, through all the gears. I was doing about 25 mph this morning in 2nd gear, punched it to get around a truck and the rearend got loose. The traction control was on so it straightened right back up. I'm very happy with the 4.10's, even cruising at 70mph. I need to correct the speedo but Im trying to figure out what tuners in the area can do for me, without getting a dynotune right at the moment because I have a few small engine mods I want to do before I get her dynotuned.