I've been told several times that my 84 K10 with a weak 305 would benefit from swapping my puny 3.08 gears over to 3.73 gears. I've been told my a bunch of people that it will make a huge difference to the way my truck feels on the road. I have a 305 with a freshly rebuilt 700r4 transmission and would love for it to not feel like a tired, old, sluggish truck. What all would I have to change? Surely I would have to do something up front to or my 4wd would be all out of whack. Opinions and personal experiences are very welcome as I'm not really sure what to expect. Since I have overdrive will I notice a huge dip in mpg on the highway?