I have an 07 GT that is supposed to have a set of pro 5.0 390 forged gears in it. My question is... in fifth gear, at 60 miles per hour, what should my rpm be? I had a 98 cobra with 4.10's but that's a dif. car, dif. rpm range. If anyone can help me, it would be much appreciated! I'm new to these cars, and am still learning of their limits and performance. I know about the typical, jack up the car and rotate the drive shaft, but, was just wondering if anyone out there has a simular setup, and if you guys could help me with some info on engine rpm based on these gears. Thanks.  

I'm pretty sure 2000-2200rpm range sounds right  

Ok, that is what I am getting. In fifth gear it is around 2100, or so. Can you tell me how you came up with that figure, just so I'll know?  

I had a fox body GT with 3:73 gears that got 2000rpm at 60 mph, with your 4:10s it will be slightly higher 2200rpm sounds right,ballpark anyway  

Thanks. I drove the car for a while, and with the 3.90's I was cruising at 2150 or around that. Appreciate the help.