I swapped from 3.55s to 4.10s in an older project of mine. I changed so many other things that the drop in quarter mile times cannot be attributed to anything in particular, though. I went from 13.5s to a best of 11.96, but I also picked up 50 rwhp at the same time.
That said, I believe that with sticky tires, you would see a very nice improvement in your 1/4 mile times, but probably not half a second. 4.10s are fine for the street as long as you don't spend a huge amount of time on the highway, but honestly a lot of 4cyl imports have terrible final drive ratios, too. They don't have a gear as tall as we do in 5th, either. My '95 BMW 318i is running at 3000 RPM at just 70 mph. You won't be running that high, even after the gear swap to 4.10s.
Back to the drag racing part, if you're looking for improvement, sticky tires should come first. The 4.10s will only help you in the first part of the track. If you just blow off the tires on the launch, then those gears aren't doing anything for you.