[bigdrake]

I'm fairly certain mine has 3.55:1 gears in it, and I really have no desire to do serious performance mods, but wear and tear may require replacing a few parts in the rear axle, and I figured if I do it, now might be the time.

Question - would 4.10:1 make the truck useless on the highway? If so, what would be the ideal gearing that would be "the best bang for the buck" so to speak, where it's still driveable, but it's got a little more grunt...

 

[tdimark]

the difference between the 3.55 and 4.10 at 65MPH with a 5 speed trans is only 200rpm. if you tow the 4.10 are much better in my opinion. if you have an automatic trans you probably have the 3.07 gears(takes a different carrier and cannot accept 3.55 or 4.10 gears) i average 20 mpg with 4.10 gears/5 spd. either way tag should be on rear or look under the hood for option sticker(if its still there)

 

[bigdrake]

So with the auto, I can't bump the gears at all? I'll do some looking to see what gears are in it...

 

[Pond_traveleR]

4:10's wouldnt make it useless on highway, my buddies 89 cummins would go bout 140 with em unloaded with a 5spd, then he got a 3200 rpm governor spring and he can go 160 now

 

[bigdrake]

Well - the auto truck ended up being a bit of a bust, it's gone, and I found another one that actually is a five speed, that I can work with.

I'm finding that the 3.55 gears just don't quite have that "edge" I'd like living in hilly/mountainous terrain. If I bump to 4.10s, will I have to change anything to make sure the speedometer and odometer are correct?