MikeC, I had 3.42 gears in the rear of my 59 Suburban. (79 K5 Blazer 12-bolt rear). I ran 31/10.50-15 tires on it, I had no problem going down the freeway at whatever speed I wanted (top was over 100). I was running a 350 though, not a 6 banger. Although not a 1 ton, it did weigh close to 5500 pounds. I agree with Grigg though, put a tach on it so you know exactly how fast the engine is spinning.
