1/2 ton axle info?

[Kaysenmc]

Hey, I'll start by telling what I have and go from there. My rig is an 86 K5 with the stock axles, and I am thinking of doing a gear swap and installing a locker in the rear. What gear ratio would you suggest for my rig, currently I am running a weak 305, 700r4, with 35's. But I plan on going to a 36 when mine wear out. I do most of my driving around town/ highway, but it does go to the river pretty often (4-5 times a month). So which gear ratio would be good for all? With the stock 3.42's it very seldom goes into overdrive on the highway (almost always just run in third, and makes the lil 5.0l scream in second to pass), and is absolutely gutless in the mud/sand. I have also been thinking of doing a 3/4 ton swap, suggestions? Please help, because I kinda hate to pull a perfectly fine engine and still only spin one in the dirt. Thanks in advance, Kaysen