I just did the 410 to 3.55 swap in my 97 cc 5sp. I do not tow anything much with that truck, and so far I am very pleased with it. Before at 65 in 5th I was at 2200rpm now its 18-1900rpm at 65 2200rpm is around 75. I like the 3.55's way more for interstate driving, I know that!!!
Again, this whole concept is pretty silly. If you don't tow, and want good mileage why don't you do this... Buy a $2000 honda civic as a DD and get 34-36 mpg. That's what I did in college, saved me alot of money. Fuel savings paid for the whole car in the span of only 1 year.
I only drive my truck as my DD now because I'm always traveling and need something to carry my big mac toolbox along with my other ****.