Its totally doable. I had a 81 Blazer with 3.08's and 35's. With a 3 speed auto and a 383 pushing 350hp and over 400 pounds torque. I ran this a couple months til I could afford 4.56's and a detroit. A 86 Blazer with stock tires, stock 160hp motor could take me. Your mileage will suck, the tranny will be working hard, you'll be slow, and the off roading will not be very good, but its possible. Get some 4.10's or 4.56's if you dont go over 65 MPH. Or if yer broke find a junkyard with a wrecked explorer that had limited slip 3.73s n take those axles. 33s with 3.73s is still better than your gears n stock tires. It comes out to like a 3.4 gearing.