An interesting question. Lets figure this out:
According to Ford, the transmission ratios 1-6 are: 4.236, 2.538, 1.665, 1.238, 1.00, 0.70.
The tire Revolutions Per Mile are either P225/60R17 = 753 (base), P235/50ZR18 = 765 (mca or pony pack), 255/40R19 = 738 (perf pack).
I used this tool to crunch the numbers, since I didnt feel like doing it myself. One drawback to this page is that it gives static revolutions per mile based on tire size alone regardless of what the tire maker says it should be, but for an estimation it's close enough:
Assuming no speed limiter, 6850 rpm redline and in sixth gear.
2.73 gears in a base v6 you get 295mph
2.73 gears in a mca v6 gives 291mph
3.31 gears base is 242mph
3.31 mca is 239mph
perf pac only comes one way (3.31 and 19" wheels standard) and comes out 237mph
These of course are impossible figures since we aren't taking into consideration air drag. as a matter of fact, the only cars that hit these kind of speeds are hypercars like the 1000hp Bugatti Veyron and even then it has to be put in a special "high speed" mode where it closes all the spoilers and drops its suspension to the ground. So, lets run the numbers again in 5th gear which is a 1 to 1 ratio:
2.73 gears in a base is 206mph
2.73 gears in a mca is 203mph
3.31 gears base is 170mph
3.31 mca is 167mph
perf pac is 166mph
Now, these are closer to real life I suppose and if theoretical is all you're after then they're good enough.
With a blower, maybe the Perf Pac car could pull redline in fifth. I really don't know.