[RIDE-RED 350r]

I hear you there.

So, you have the overdrive auto then?? I have been told it's basically the non-electronic 700-r4...

3.08 seems aweful high for my taste in a later K-10 with OD Auto trans...

What size tires are you running??

My brother has an '85 K-10 with the OD Auto trans and 33" tires. He just had his re-geared to 4.10 from 3.08 and likes it much better being as he hauls a 19' Fiberglass I/O boat. In OD if I remember correct, he is turning about 2000 RPM at 60 MPH. His truck had 3.08 in it when he got it and had all sorts of trans shifting issues, particularly with converter lock-up at highway speed. It would kick down if he hit more than a 2mph head wind on flat ground! Turned out, the 3.08's were just too high a ratio for his transmission and tire combination. TOTALLY different truck after the switch to 4.10 gears!

If you are still running stock tire size I think 3.73 might be a better fit for you and give you a more noticeable kick in the pants in power to the ground.

My '78 with 4spd, 3.73 and 35" tires on the other hand... bout 2400 RPM at 60mph. But I am very happy with it for what I use my truck for.

You definitely need to figure out what quality is most important to you.... pulling power or fuel economy. Where your compromise should be is really to be determined by you and how much value you place on those 2 things for what you do.

Quick question: Have you confirmed your front axle ratio?? I ask because I don't think that 3.08 gears are common original gears on the 4x4 trucks. I could be wrong and will stand corrected if so. But regardless, someone has played around in the rear end, I would make sure your front axle ratio matches before using 4x4. You may laugh, but I have seen this with 2 old K-10s in the last couple of years. People at some point decided they needed a re-gear for their intended every day use and only re-geared the rear diff not touching the front... Very interesting seeing a truck attempting to use 4x4 with mismatched axle ratios!