I recently swapped from stock (3.27 gears) to 3.73 gears. I have noticed some difference,
but not as much as I had hoped for. Most guys on this forum recommend the 4.10's.
I went with 3.73's because I drive 20 miles each way to work between 60-70 mph. With the 3.73's, in OD, I am at 2000 RPM at 60 MPH. At 70, I am just under 2300. According to the rear axle calculator I used, with 4.10 gears, I would be at 2500 RPM at 70 MPH in OD.
Here is the Rear Axle Calculator I used...seems to be dead on:
MOTOR - A Rear Axle Calculator
If I had it to do over, I believe I would try the 4.10's...the RPM's aren't that much different and the NA 4.6L 2V engines seem to like higher RPM's, not off the line performance.
