I would have thought that a 4.10 rear end would get you over 60 mph. I have a stock drivetrain (216, 4-spd, 5.14 rear) and new 31" tires on 17s, but I've only braved the speedo up to 48 mph in town. There are online calculators that can estimate top speed with some basic info, like final drive ratio (max rpm, gear ratio, etc.) and tire size.
I worry about skinny tires at higher speeds (>60 mph), that's why I invested in wider tires. Handling is great! Tire size can also have an impact on power at the wheels, but I don't think your trying to get to 60 in under 4 seconds!
