If a want speed which rear end gear ratio should I have. And which for hilly terrain?. If a get a faster more rpm ratio can I mora powerful engine offset for uphill driving, which ratio best for fuel economy & performace?, thanks (RE: 1992 Bronco I-6 300, C-6 tranny, 2Wd stock).

 

With gear ratios, the lower the number, the higher the ratio and the slower the engine will turn for any given vehicle speed.

3.08 is considered a high ratio in a pickup. It is good for freeway cruising but doesn't give much power.

4.10 is considered a low ratio and is good for towing/hill climbing power, but with a non-overdrive transmission your top speed on the freeway will be limited depending on what size tires you have.

Your Bronco probably has a 3.55 ratio, but you really should look up the info on your door sticker under axle and then go to the tech articles section of this website and look in the axle decoder to find out what ratio you have now before making plans to change it.

Also, tire size makes a big impact on gear ratio and no new ratio can be decided on untill you know what your tire diamter is, in inches.

Yes, a more powerful engine that also makes it's power at a lower rpm can pull a higher gear ratio and still have descent power. Conversely, a small engine that makes it's power at a higher rpm will be a real dog with a high gear ratio.

If your Bronco has stock tires on it, a 3.55 ratio will likely be fine. A 3.73 ratio would be good if you intend to tow anything. I'm not a big fan of high ratios in trucks so personally I wouldn't go any higher (numerically lower) than 3.55.